Running in the Family is written by a Sri Lankan-born Canadian novelist and poet, Philip Michael Ondaatje. He is best known for writing The English Patient. But this book is not a work of fiction; instead, it is something of a memoir from his youth in Sri Lanka (then known as Ceylon). It is partially fictionalized. The book is written in close to postmodern style, with stream of consciousness writing, writing from the perspective of different real-life individuals and refraining from stringing narrative together in an orderly fashion.

The focus of the book is Michael's family. The Ondaatje family had lived in Ceylon for centuries, so he has a large number of relatives who live there. The main focus of the book is on his alcoholic father, Mervyn Ondaatje. He also focuses on his outrageous grandmother Lalla.

In the acknowledgments, Michael notes that his book is a "composite," or a mixture of his two return journeys to Sri Lanka in 1978 and 1980. He stayed for months each time, first travelling alone and then with his family. He and his sister Gillian also researched around the island. Gillian, his sister Janet and his brother Christopher helped him to recreate the era. His raw material came from numerous friends, family and acquaintances across the island.

The book explores a variety of themes, among them are family, social expectations, addiction, the memory of youth, and loneliness. Ondaatje is focused primarily on exploring his family and these themes; as a result, the book is not structured around a single narrative. It is comprised of seven large chapters that contain various sketches of memories, interviews and reports that are separated as sub-chapters. For instance, Chapter 1, "Asian Rumours" has two sub-chapters, "Asia" and "Jaffna Afternoons." The first sub-chapter covers Michael's return trip to Sri Lanka and the second mostly discusses the old governor's house on the island.

The other six chapters cover more general topics. Chapter 2, "A Fine Romance" discusses his parents' meeting and their marriage along with a variety of other small but related matters. Chapter 3, "Don't Talk to Me About Matisse" explores Ceylon, its history, geography, flora and fauna. Chapter 4, "Eclipse Plumage" is about Michael's grandmother, Lalla. Chapter 5, "The Prodigal" outlines his father's alcoholism and his outrageous antics as a young man in Ceylon.

Chapter 6, "What We Think of Married Life" explains his parents', Doris and Mervyn's marriage and the problems they faced, largely due to Mervyn's drinking. And in Chapter 7, "The Ceylon Cactus and Succulent Society", Michael covers Mervyn's sad decline into depression and obesity, lamenting the fact that his father would never let him and his family into his emotional life.

While the book is fictionalized, Ondaatje notes that, "In Sri Lanka a well-told lie is worth a thousand facts." The reader must approach the book knowing this ahead of time, understanding the author is drawing a "portrait" or making a "gesture" towards his youth in Ceylon and his family. The point of the book is to draw out the themes from his youth, not necessarily to record his history as it truly was.