The objective was to study the effect of "academic group detailing" on the prescribing of lipid-lowering drugs in Swedish primary care. A randomized controlled trial was conducted, randomization being by group. Groups of doctors at 134 community health centres were randomly allocated to an intervention and a control group. The 67 intervention health centres were offered four sessions, conducted by a pharmacist, with group information on guidelines for the management of hyperlipidaemia. The number of prescriptions of lipid-lowering drugs per month increased in the intervention health centres and the increase was statistically different from the corresponding change in the control health centres among women in the age group 30-65 years (p = 0.03). The prescription of first-line lipid-lowering drugs increased by 20% in the intervention health centres (p = 0.03). "Academic group detailing" by pharmacists to primary care doctors can be an effective method for influencing prescribing practices.