BACKGROUND Calcium channel blockers may increase the blood flow to the fetus or may improve fetal-placental cellular energy generation. This could enhance fetal growth. OBJECTIVE The objectives of this review were to assess the effects of calcium channel blockers on fetal growth and neonatal morbidity and mortality in pregnancies where impaired fetal growth is suspected. METHODS We searched the Cochrane Pregnancy and Childbirth Group trials register and the Cochrane Controlled Trials Register. Date of the last search: December 1999. METHODS Acceptably controlled trials of calcium channel blockers in women with potential impaired fetal growth. METHODS Eligibility and trial quality were assessed. RESULTS One study of 100 women (all smokers) was included. Mean birth weight was significantly higher in women receiving flunarizine compared to the control group. No other significant differences were found. CONCLUSIONS There is not enough evidence to evaluate the use of calcium channel blockers for impaired fetal growth. The apparent beneficial effect of calcium channel blockers on birthweight warrants further investigation.