In 2001 Nia Vardalos wrote the script for the lighthearted movie My Big Fat Greek Wedding, the story of a 30 year old American woman of Greek descent who falls in love with someone who is not of her Greek heritage. With humor, insight, and skill, the movie presents the challenges of good-enough family relationships, strong cultural expectations, developing a healthy self-esteem, and the importance of cooperation and mutual respect for individual differences.  Ultimately, love conquers all between loving people.

The story line begins explaining the family and cultural dilemma in which Toula (played by Nia Vardalos) finds herself. She isn't married and feels like a failure in life and in love. Unlike other family members, she hasn't met a nice Greek boy, made babies, or left home; something her family reminds her of regularly. She is a disappointment to herself and others as she daily helps her parents run the family restaurant.  Having settled for mediocrity, she's overweight, unattractive, and cynical about her future. One day while hosting at the restaurant she sees an attractive man (Ian Miller played by John Corbett) talking to friends, as their eyes meet she loses her concentration, spills coffee, and is mortified that she accidentally embarrassed herself in front of him.

Toula decides to make a radical change in her life. She wants to go to college to learn about computer applications. Change is hard for a close-knit Greek family and her typically stubborn father Gus, resists the idea. Toula is needed at the restaurant. Seeing the situation, mother Maria knows how to handle her hard headed husband and gets approval for Toula to follow her dream.  Toula has hope, ditches the bottle-cap glasses, slims down, discovers make-up, and attends a computer class on tourism. A plan formulates: she can use her computer skills to work for her aunt Voula's travel agency.  The opportunity arises when aunt Voula and uncle Taki want to take a vacation.

Toula is happy in her new job.  One day she notices that someone keeps looking at her through the window while she is working. She realizes it's the same young man she saw in the restaurant. Fearing recognition, she tries to avoid his attention, but to no avail. Intent on seeing her, the young man falls and makes them both laugh. Toula and Ian, a teacher at the local high school, meet and make a date for dinner. It doesn't take long before they both realize they are falling for each other.

Toula's predicament doesn't get easier. Ian isn't Greek and she knows that will be a problem for her family.  She isn't sure what to do. Even when she admits to being the same clumsy waitress Ian first encountered Ian reassures her that he really enjoys spending time with her and wants to see her more. They share their first kiss.  At a loss for how tell her parents, Toula tries to keep Ian a secret for awhile, but they're soon seen together at the travel agency by Nikki and everyone hears about it. Gus throws a fit, and does his fatherly duty to introduce Toula to some “proper” Greek boys who prove to go from ad to worse as potential suitors.

It's clear to both Toula and Ian that their relationship is strong and heading toward something permanent. At her family's Easter festival, it's discovered that Ian is vegetarian, a near crisis for Toula's restaurant family.  In spite of this rather tenuous start, Toula and Ian are determined to work out the differences together, and soon Ian proposes. Toula accepts, and with Maria's help, Gus must finally accept that his daughter isn't going to marry a Greek. As a gesture of solidarity, and to ease family feelings, Ian is baptized into Toula's strong orthodox faith.

After meeting Ian's very conservative parents for the first time, Toula is not sure how they will react to her large, eccentric, and unpredictable family. The families plan a quiet engagement dinner, and Toula is horrified to learn that her mother has invited all of the relatives to attend.  The differences in the cultural expectations are humorously obvious when the dinner becomes a chaotic series of noise, too much food and wine, and language barriers. Ian's attempts at speaking Greek get him into trouble when Khristos Anesti sounds like “Cheese straws are nasty”. Of course, Toula's relatives take full advantage of his lack of skills.

The wedding details go far off course when, in their excitement and without permission, Maria and the female relatives begin planning a big “traditional” Greek wedding in order to help.  Ian's mother's name is misspelled on the elaborate (and very Greek) invitations, the out-of-style and flamboyant bridesmaid dresses are a nightmare, and Toula has not been consulted when her “snow-beast” wedding dress is revealed. Ian takes it all in stride and helps calm Toula through each crisis. Even her large zit on the wedding day is covered over and the wedding goes off without a hitch.

At the reception it is clear that everyone has made an effort to get along and understand one another. The pride and joy of each family is evident as they welcome the joining of the two families, each accepting the differences and for the sake of their children trying to find common ground. As the movie ends, Toula and Ian are living in the house provided for them by Gus and Maria, another Greek tradition. The house is next door. Even so, Ian and Toula and their little daughter Paris are happy, relatives and all.  In the closing scenes, Toula tells her daughter that she will be going to a Greek school, but when she's older she can marry whomever she wants.