Frank, our narrator, author and protagonist, begins the memoir with a regret: he and his family should have stayed in New York. He describes how his parents met, wed, and had five kids in New York but are now on a ship heading back to Ireland after the death of Margaret, Frank's little sister. Margaret's death caused Angela and Malachy Sr. to spiral into depression (and Malachy Sr. into even worse drinking) and to neglect their still very alive brood. Conditions in New York become desperate, and they think that they should be around family back home.
But things in Ireland aren't any better. Grandpa and Grandma McCourt don't want anything to do with them and they end up in Angela's hometown of Limerick. Angela's mother sets them up in a small flea-infested room. Malachy Sr. signs up for the dole; it's barely enough to cover food, rent, and clothing and Angela's forced to go to the St. Vincent de Paul Society to get food vouchers. In six months, Frankie's twin baby brothers are dead from disease and malnutrition.
Angela's unable to continue living in the same home where the boys died and so the McCourts move again to another rundown house right in front of the only latrine for the entire lane. In the summer, the stench is unbearable. It also floods during the rainy season. Angela gives birth to another baby boy, and Malachy Sr. gets a job at the cement factory but loses it after he goes on an all night bender and doesn't wake up for work the following day. Through all this deprivation, Angela tries to give her sons a warm and loving home but she's clearly totally stressed out.
Malachy Sr. spends the next several years either unemployed or between jobs. He loves his kids and spends a lot of time with Frank, but his lack of ambition and serious drinking leave the family hungry, cold, and broke. Frank's a resourceful kid who loves Shakespeare and movies and dreams of being able to help out his family and move back to America when he grows up. He gets odd jobs that bring in a few shillings here and there. He survives a serious bout of typhoid fever and spends fourteen weeks in the hospital.
WWII is erupting and Malachy Sr. gets a job in a munitions factory in England. He promises to send his family money when he gets paid, but true to form, he ends up drinking it all away. The McCourts are soon evicted from their home and have to move in with Angela's cousin, Laman Griffin. Frank and Laman have a huge falling out and Frank moves in with his uncle. He gets a job at the post office delivering telegrams. Frank meets Theresa Carmody while delivering a telegram to her home. Since Theresa is dying from consumption she "knows there's little time left and makes them [the telegraph boys] mad for love." (15.103) Frank loses his virginity to Theresa. She dies a few weeks later and Frank's convinced he's doomed her to hell until a kind Franciscan priest reassures him that's not the case.
Back at the post office, there's a possibility for a permanent position and Frank's all ready to take the exam until his Uncle Pa tells him, "If you pass the exam you'll stay in the post office nice and secure the rest of your life" (16.83). In other words, it'd be saying goodbye to Frankie's dream of returning to America. Frank decides not to take the postal exam and gets a job distributing newspapers and finally saves up enough money to go to America when he's nineteen.
Due to the tide, Frank's ship is forced to dock in Poughkeepsie. Sometime in the middle of the night, an Irish fellow invites Frank and a few others ashore. The men end up at a party and Frank ends up sleeping with one of the women there. Once back on the ship, Frank stares at the twinkling skyline and reflects on his new life in America.