In this article is described problems of bronchioloalveolar carcinoma, with respect to increased incidence of adenocarcinoma and bronchioloalveolar carcinoma. It was observed that bronchioloalveolar carcinoma occurs more frequently in younger persons and in women. Etiology of bronchioloalveolar carcinoma is still unknown. There is not an obvious connection with smoking but connection with previous damage of lung parenchyma. Bronchioloalveolar carcinoma can be defined as neoplasm which is not of central origin , but is peripherally located; therefore the term "bronchiolo-" but not "broncho-alveolar" carcinoma. It grows along alveolar septa and lung parenchyma remains intact. There is three pathohistological subtypes of bronchioloalveolar carcinoma: mucinous, non-mucinous and sclerotic form and three radiological patterns: solitar, pneumonia-like and diffuse. Clinical features depend of the stage and patient are most frequently asymptomatic. They later present with chest pain, dyspnea, cough, hemoptysis and weight loss. Complications include bronchorrhoea and intrapulmonal shunts. These findings, together with laboratory analysis, radiological tests (including CT scans) and cytological or hystological proof of malignancy, make definite diagnosis. Therapy depends on the stage of disease and is identical with that of other subtypes of non-small-cell lung cancer.