The story begins with a family planning a road trip from Georgia to Florida. The family consists of the grandmother, her son Bailey, his wife, and their three children: John Wesley, June Star, and a baby. The grandmother, who lives with the family, tries to persuade them to visit Tennessee instead, warning them about a criminal known as The Misfit who has escaped from prison and is headed towards Florida. However, the family ignores her advice.

On the morning of the trip, the grandmother is the first to get ready. She secretly brings her cat, Pitty Sing, along, despite knowing that Bailey, her son, would not approve. As they drive, the grandmother reminisces about her past and the way things used to be, showing her attachment to the old South.

The family stops at a diner called The Tower, run by Red Sammy Butts. The grandmother engages Red Sammy in a conversation about how the world is changing, lamenting how you can’t trust people anymore. Red Sammy agrees, saying, "A good man is hard to find," hence the story's title.

As they continue their journey, the grandmother suddenly remembers a plantation house she visited as a young girl. She convinces the children to pester their father into taking a detour to see the house. Bailey reluctantly agrees. As they drive down a dirt road, the grandmother suddenly remembers that the house is not in Georgia but in Tennessee. Startled by her mistake, she accidentally lets the cat out of the basket, causing Bailey to lose control of the car, which crashes in a ditch.

While they are stranded, a car with three men, including The Misfit, approaches. The grandmother immediately recognizes him, which seals the family's fate. The Misfit orders his accomplices, Hiram and Bobby Lee, to take Bailey and John Wesley into the woods. Soon after, shots are heard, signaling their deaths. The same happens to the mother, the baby, and June Star.

During this time, the grandmother desperately tries to save herself by appealing to The Misfit's better nature, insisting that he is a good man and that he wouldn't shoot a lady. She talks to him about Jesus, trying to convince him to pray. However, The Misfit, who is polite but detached, reveals his skepticism about religion and questions whether Jesus really raised the dead. He explains that if Jesus did raise the dead, then everyone must follow him; if not, there is no point to life.

In her final moments, the grandmother, in a gesture of grace, reaches out to The Misfit, calling him one of her own children. In response, The Misfit recoils and shoots her three times in the chest, killing her.

Afterwards, The Misfit reflects on the grandmother's final gesture, remarking that she might have been a good woman if someone had been there to shoot her every minute of her life. He adds that there’s "no real pleasure in life" before telling his accomplices to clean up the scene.