Abstract: A cross sectional study was conducted in Debre Birhan town from October, 2013 to April, 2014 with the aim of estimating the prevalence of ovine lungworm infection, to assess associated risk factors and identify lungworm species involved in the area. A total of 371 fecal samples and data were collected. Species identified using Baerman technique to extract L1 larvae. The finding indicated that 209(56.3%) were infected with two species of lungworms namely; D. filaria (78.5%), M. capillaries (16.3%) but P. rufescens was absent. Mixed infection was observed in 5.3% of the cases. There was a significant difference (p<0.05) in the prevalence of lungworm infection as compared within body condition scores, where poor body conditioned sheep had 96.9% (62/64), medium once had 5 3.9% (132/245) and good body conditioned once had 24.2% (15/62) prevalence. Difference also observed between de-worming status, those de-wormed group had 10.8% and non de-wormed had 78.1% prevalence with significant difference (p<0.05). The prevalence of lung worm within age groups and sex were insignificant (p>0.05), though there was minor prevalence difference among age groups and sex. However, Menze breed and exotic cross breed was significant in univariate (p<0.05) but insignificant (p>0.05) with multivariate logistic regression analysis. The study revealed that lungworm is very important and high prevalence of verminous pneumonia was do to two lung worm species regular and strategic de-worming has significant impact in controlling parasite infection. The situation dectates that prompt action has to be implemented by organizing stakeholder in the area particularly and in the country in general.