Background: Nocardiosis is an opportunistic infection and most commonly presents as pulmonary disease. Unless investigations like Gram’s stain and modified acid-fast stain are specially done, pulmonary infection may be mistaken for tuberculosis. They are useful for early diagnosis of Nocardia infection. Hence, the present study was conducted for the early detection of pulmonary nocardiosis mimicking tuberculosis by sputum microscopy with Gram staining, modified Ziehl-Neelsen (ZN) staining. Material and methods: The current study was conducted on 2,466 sputum samples over a period of 4 years from July 2011 to June 2015 for ZN staining for evaluation of pulmonary tuberculosis. Those sputum samples which were negative with 20% H2SO4 and showed weakly stained acid-fast bacilli (AFB) were confirmed for Nocardia by modified ZN staining with 1% H2SO4, Gram’s staining and culture. Result: Out of 2,466 sputum samples, 433 (17.55%) were found positive for AFB by microscopic examination. Ten (2.30%) out of 433 cases were positive for Nocardia. Amongst the Nocardia positive samples 7 (70%) were of male and 3 (30%) were of female. Conclusion: Gram’s staining and modified acid-fast stain are useful for early diagnosis and appropriate treatment of pulmonary nocardiosis.