The features of bronchoalveolar lavage fluid (BALF) components and the severity of pulmonary alveolar proteinosis (PAP) were analyzed in the first Romanian cohort of patients admitted to "Marius Nasta" Institute of Pneumophtisiology, Bucharest, Romania. A six-year follow-up study based on bronchoalveolar lavage (BAL) data was performed between January 2007 to December 2012. Study cohort consisted in 20 inpatients diagnosed with PAP, based on BALF cytological findings and÷or on histopathological findings. Demographic, medical history, tobacco use, clinical and radiological features, disease progression with or without whole lung lavage (WLL) therapy were collected. Disease severity was evaluated by pulmonary function testing including spirometry, blood gas analysis, plethysmography, and diffusing capacity of the lung for carbon monoxide (DLCO), also known as transfer factor (TLCO). The cellular profile of all BALF specimens was analyzed. Statistical analysis made by SPSS version 17.0 included Student's t-test, chi-square test and ANOVA. Mean age of the subjects was 43±16.59 years, with male predominance (n=12; 60%). Diagnosis of PAP was facilitated by fiberbronchoscopy (FBS) with BAL in 90% of cases. Cytological findings of BALF revealed lower macrophages (57.26±18.19%), with a preponderance of neutrophils (17.75±19.44%) and lymphocytes (21.8±16.12%). Lower oxygen partial pressure was identified in elders, comparing to younger patients (p=0.038). Patients treated by WLL had a lower total lung capacity (TLC) and DLCO versus those who did not required WLL (p=0.009, respectively p=0.056). The severity of pulmonary abnormalities provided WLL indication was not influenced by BALF cellularity.