The epidemiology and burden of varicella was assessed through the prospective study of 683 children under 15 years, by 58 primary care paediatricians working on seven autonomous communities of Spain. The mean age was 4.5+/-2.7 years, and 566 (83%) were secondary cases. There were 111 complications in 101 children (14.8%), skin superinfection being the most frequent (8.9%), followed by respiratory tract (4.5%) and eye (2.2%) infections. The mean number of visits to the paediatric clinic was 1.42 (95% C.I. 1.37-1.47), and 5.6% of the children were attended in the emergency department of a hospital previously. All children had at least one prescription, being antihistamines and antipyretics the most prescribed. Thirteen percent received systemic antibiotics and 11% acyclovir. Children were mainly cared by grandparents, and parents were off work for a mean of 0.97 days (1.61 if children under 5 years attended day-care facilities; 0.51 if they did not). Costs derived from medical attention totalled 32.5, and social indirect costs were 63.77.