Objective: The objective of this study was to evaluate cytoprotective effects of soyabean oil supplementation against interstitial fibrosis induced in lungs of adult mice by Bisphenol A. Study Design: Experimental Study. Setting: Department of Anatomy, Army Medical College, Rawalpindi. Period: Nov 2015 to Nov 2016. Material & Methods: Forty healthy adult BALB/c mice of 9 - 11 weeks of age and weighing from 30-37gms were included in this study and were housed in controlled environment of animal house of NIH, Islamabad. Group A animals (10) served as controls. Group B animals (10) were given BPA orally at a dose of 50mg/kg body weight/day and Group C animals (10) were given soya bean oil at a dose of 500mg/day and Group D animals (10) were given BPA and Soya bean oil at doses of 50mg/kg body weight/day and 500mg/day respectively. All doses were administered orally once daily for a period of eight weeks. Animals were dissected 24hrs after receiving the last dose. Lung tissue specimen processing and Masson trichrome staining was done for the histological study. Lung interstitial fibrosis was morphometrically and statistically analysed using SPSSv21. Results: Microscopic examination showed Grade 2 interstitial fibrosis in 80% specimens in Group B, whereas only 60% specimens of Group D had Grade 1 interstitial fibrosis. Conclusion: It was concluded from results that BPA produces interstitial fibrosis and con-concomitant administration of soya bean oil diet protects against development of lung interstitial fibrosis.