The carcinoid syndrome occurs in about 10% of patients with carcinoid tumors.The main objective of the present study was to determine the presence of the carcinoid syndrome in a group of patients with carcinoid tumor.35 pts with carcinoid tumors (group A--24 pts with metastatic disease, group B--11 pts after resection of the primary tumor with no metastases detected at the time of the investigation) were included into the study. The localisation and the diameter of the primary tumor were ascertained. Somatostatin receptor scintigraphy--Octreoscan and echocardiography were done. The urinary excretion of 5-HIAA was performed. We estimated the presence of the carcinoid syndrome in all patients.We confirmed the difference in the diameter of the primary carcinoid tumor in patients with metastases--group A 3.0 (2.5-4.2) cm by comparison with group B 0.7 (0.6-0.8) cm, (p < 0.001). Patients in the metastatic group are older 64 year (42-70) than pts without metastases--33 y (20-54) (p < 0.01). The amount of the 5-hydroxyindolacetate acid in urine in pts with metastatic carcinoid was statistically significantly higher than in the pts without metastases (p < 0.001). The carcinoid syndrome in the metastatic group was found in 6 patients (25%), with maximum (12.5%) localised in midgut. Out of the whole sample it counts up to 15.1%. During the follow up period, 8 patients from group A died.The large diameter of the primary carcinoid tumor and the higher age are the bad prognostic factors in patients with carcinoid tumors. (Tab. 4, Ref. 27.)