This study describes the discovery and diagnosis of malignant tumors from a primary care perspective in a Swedish county. Between 1984 and 1995, 68 children between the ages 0-16 years were diagnosed with a malignant tumor giving an incidence of 14/100,000. Patient records from both primary care and hospital were analyzed for 64 children. Leukemia was diagnosed in 25 children, and brain tumors in 22 children. In 68% of the children the diagnostic process was initiated in primary care, and in 32% in specialist care. Median parent's delay (time from first symptoms to first consultation), and median doctor's delay (time from first consultation to diagnosis) were 5 and 3 weeks for children with brain tumors, and 1 and 0 weeks for children with leukemia. Median lag time (parent's + doctor's delay) was 9 weeks for patients with brain tumors and 3 weeks for children with leukemia.