introduction: few brazilian papers on the use of medication in pregnancy have been found in the indexed medical literature. this paper describes the use of medication during pregnancy among women who gave birth in a teaching maternity hospital in the city of campinas, brazil. methods: a retrospective study on the pattern of drug use during pregnancy was conducted among 1,000 mothers who were interviewed using a structured questionnaire after delivery, while they were still in hospital. the following parameters were registered: sociodemographic characteristics, obstetric and contraceptive history, data on prenatal care and medications used during pregnancy. statistical analysis was performed using anova and chi-square test at p = 0.05. results: among the interviewed patients, 94.6% had taken at least one medication during pregnancy, and 46.1% had used medication in the first trimester. of 3,778 medications reported, 88.8% had been prescribed by a doctor. the median of medications taken was 3 (ranging from 0 to 18). the six most used classes of medications were: analgesics, spasmolytics, gynecological antiinfectious agents, antianemics, antacids and systemic antibiotics. the five most used medications were: butyl scopolamine, ferrous sulfate, dipirone, nistatin and multivitamin tablets. only 27.7% of the patients had been alerted to the risk of taking medication during pregnancy. conclusion: knowing the profile of medications used during pregnancy may help devising programs to provide information to the patients and continuing education to health care professionals.