The aim of this study was to compare the clinical characteristics, histological type, stage at diagnosis, treatment and survival of young (< or = 45 years) and older patients with bronchogenic carcinoma. The study was designed as a retrospective review of all lung cancer patients referred to the Kuwait Cancer Control Center over a 10-year period from 1985 to 1994. The study comprised 590 patients with primary bronchogenic carcinoma, of whom 72 (12%) were < or = 45 years of age at the time of diagnosis. Median (range) duration of symptoms, percentage of smokers and male to female ratios for the younger and older patients were 8 (2-48) weeks vs. 8 (1-52) weeks (p = 0.9), 74% vs. 83% (p = 0.06) and 5.5 vs. 5.3, respectively. The majority of patients had advanced stage disease at presentation; 91% of the younger patients had stage III or IV compared with 88% of the older patients (p = 0.1). The histological types for the younger and older patients were 32% vs. 20% for adenocarcinoma (p = 0.01) and 33% vs. 45% for squamous cell carcinoma (p = 0.1). There were more patients in the younger group who had surgery (21% vs. 7.5%) than in the older group (p = 0.001). Follow-up data were available for 177 patients out of 190 Kuwaiti national patients (93%). The median (range) survival rates for young and old patients were 8 (3-62) months and 7 (1-174) months, respectively (p = 0.09). Only 6 patients survived for more than 5 years, one (7.6%) from the younger group and 5 (3%) from the older group. Our study shows a relatively high percentage of young patients in our population of lung cancer patients. Apart from the higher incidence of adenocarcinoma in the young group and the fact that these patients had more surgery than the older group, there were no other significant differences between the two groups.