TGF beta 1 commonly produced by normal and neoplastic human cells, has capacity to regulate new blood vessel formation, to establish and maintain the vessel wall integrity; was found to have some significance in the lung cancer prognosis. Tumour angiogenesis is an important factor for tumour growth and metastasis. The purpose of this study was to find, if the immunoexpression of TGF beta 1 has any significance in determination of the histologic subtypes of carcinoids?; to find, if TGF beta 1 has any role and relation to carcinoids angiogenesis?; and to explore TGF beta 1 expression and angiogenesis with respect to metastatic potential of carcinoids. The study was performed on 48 resected broncho-pulmonary carcinoids: 35 typical (TC) and 13 atypical (AC), classified according to the WHO. Semiquantitative analysis for TGF beta 1 was performed. Sections stained using monoclonal antibody against TGF beta 1 were scored in scale from 0 to 4, according to the percentage of positively stained cells (pc) plus percentage of positively stained stroma (ps). The microvessels stained with CD34 monoclonal antibody, were counted in 0.75 mm2 field (microvessel density--MD), using the computerised image analysis system SAMBA 2005 (the morphometric software). The histologic subtype of carcinoids was related to age of the pts (AC occurred in older pts than TC, p = 0.027), to the tumour size (AC were larger than TC: respectively--3.25 cm and 2.4 cm, p = 0.009). Lymph node metastases were significantly more frequent in AC than in TC (38% vs 13%, p = 0.025). 85% carcinoids showed TGF beta 1 expression with various intensity, mainly in the stroma. There was no significant correlation between TGF beta 1 expression and tumour size, the histologic subtype nor the lymph node metastases. The angiogenesis expressed as MD, was not related to histology, nor to the presence of lymph node metastases. There was no correlation between TGF beta 1 expression and angiogenesis. Shown in our study, lack of relation between TGF beta 1 expression and angiogenesis, could support some of the published data indicating indirect action of TGF beta 1 on the angiogenesis. The rich vascularity found in carcinoids morphology could result from TGF beta 1, commonly expressed by the tumoural stroma. The angiogenesis nor TGF beta 1 expression do not determinate the carcinoids histology.