A prospective intensive 6-month follow-up study of adverse drug reactions in over 4500 consultations in rural medicine was performed. A total of 49 adverse drug reactions were reported and analysed. The most frequently reported side effects were cutaneous (30.6%), digestive (28.6%) and neurological (22.4%). These were mainly associated with the use of anti-infectious (22.5%), cardiovascular (22.5%) and anti-inflammatory (16.5%) drugs. This study emphasises that adverse drug reactions represent a relatively high frequency (1.1%) of consultations in primary health care in rural medicine.