We conducted a retrospective analysis of the epidemiological, etiological, clinical and radiological characteristics, and mainly of those related to the diagnosis and treatment, of all the patients with radiological criteria of solitary pulmonary nodule (SPN) studied in our environment during a period of six years (1984-1989). The incidence of SPN was 3.1% (123/3953). Among the 117 cases of filiated etiology, 83 (71%) were malignant and 34 (29%), benign thoracotomy was used as diagnostic method in 11 (32%) benign cases and in 8 (9.6%) malignant cases. Due to several causes, only 31 out of the 75 (41.3%) malignant nodules diagnosed prior to the thoracotomy underwent resection surgery. According to the selection criteria applied in our medium, a high number of the SPN were malignant; in most of these cases, the diagnosis was established without the need of thoracotomy and in less that half of them, curative surgery was attempted.