A case-control investigation of childhood acute lymphoblastic leukemia was conducted in the town of Carbonia (Sardinia, Italy). Parents of 9 cases diagnosed between 1980 and 1989 and 36 controls were interviewed at their respective residences. None of the risk factors analyzed was associated significantly with childhood acute lymphoblastic leukemia. The following were associated with an increased risk for childhood acute lymphoblastic leukemia: parents born outside of Carbonia, family history of cancer, alcohol consumption by fathers that exceeded 60 g/d, exposure of fathers to solvents at their workplaces, maternal smoking, use of antinausea medications during pregnancy, and presence of a well in the backyard. Chance and recall bias likely played a role in generating positive associations. The increases in childhood leukemia risk associated with the presence of a well and with use of antinausea medications during pregnancy are consistent with previous reports and require further investigation.