['The prognostic significance of fibroblast foci in surgical lung biopsies from patients with idiopathic pulmonary fibrosis (IPF) is unclear.', 'We assessed the relationship between profusion of fibroblast foci and survival in 43 patients with IPF seen at a tertiary referral medical center from 1996 to 2002.', 'Fibroblast foci in surgical lung biopsies were counted using a systematic morphometric point-counting technique. Patients with either clinical or pathologic evidence of accelerated disease were excluded from analysis. The association of fibroblast counts with survival was assessed using proportional hazards regression.', 'The mean age (+/-SD) of the study population was 64+/-9 years; 26 (60%) patients were male. The mean (%+/-SD) profusion of fibroblastic foci was 0.6+/-0.7, expressed as a percentage of total points counted. Fibroblast foci counts did not differ markedly between upper, middle, and lower lobes. Median survival from the time of biopsy was 2.4 years; there were 25 (58%) deaths in the follow up period. There was no significant relationship between profusion of fibroblast foci and survival in the overall group (p=0.250).'] Does profusion of fibroblast foci in patients with idiopathic pulmonary fibrosis predict outcome?