The objective of the study was to find out whether the delay in time from when bronchogenic carcinoma is diagnosed until a therapeutic thoracotomy is performed affects patient survival. The population analysed comprised 1082 patients with clinical stage I and II, non-small cell lung cancer (NSCLC), who had been operated on between October 1993 and September 1997, and were registered in the Bronchogenic Carcinoma Cooperative Group of the Spanish Society of Pneumology and Thoracic Surgery (GCCB-S). In this series, the median therapeutic delay was 35 days (1-154), with a median survival rate of 52 months (45.6-58.3). A statistical study was developed that, in addition to the delay, included the variables of age, histology, clinical stage, and pathological stage of the disease. Therapeutic delay was included in the multivariable analysis as a quantitative and qualitative variable and a comparison among the different intervals of delay in days (1-20 vs. 21-40 vs. 41-60 vs. > 60) was performed in order to ascertain its influence on survival. Univariate and multivariate Cox's regression analyses showed that age (> 70 years), clinical stage (I vs. II), and pathological stage influence survival. As for the histology and the delay, no significant differences were observed in the survival of any of the intervals even when compared against the intervals at the extremes (1-20 vs. > 60). In conclusion we found no influence of delay upon the survival.