Erythrocyte sedimentation rate (ESR), leucocyte count, platelet count, haemoglobin concentration (Hb) and survival were studied in an epidemiological material of 258 patients with bronchial carcinoma. The mean ESR was elevated (48.1 mm/h) and, more so in squamous cell and small cell carcinoma than in large cell and adenocarcinoma. Leucocytosis, over 9 X 10(9)/l, was found in 39% of the patients and thrombocytosis, over 400 X 10(9)/l, in 13% of the patients. Nine per cent of the patients were anaemic, with Hb lower than 11 g/l. There was a statistically significant positive correlation between ESR, leucocyte count and platelet count, but a negative correlation was found between these 3 variables and Hb. ESR, leucocyte count and platelet count also correlated to survival at a statistically significant level. Multiple regression analysis of these laboratory variables showed that they explain about 8% of the great variations in survival time.