Background: In the present study an attempt was made to compare the different diagnosis of mycoplasma pneumonia among the patients of respiratory tract infections in northern Indian population. Commonly used techniques in the diagnosis of mycoplasma pneumonia are culture, serology and PCR and different studies assure the different sensitivity and specificity. In the present study author also aim to find the common risk factors of mycoplasma pneumonia. Material & Methods: The present study was undertaken at Career Institute of Medical Science, Lucknow. The total number of study subjects were 193. The total number of male subjects were 115 (59.6 %) while 78 (40.4 %) were females. Samples were Collected for culture, serology and PCR. All samples of culture & serology were undergone for PCR. Results: Out of 193 patients 58 (30 %) samples were found positive in culture and 73 (38 %) samples were found to be positive in serology test. 58 patients were found to be positive by both culture and serology which are further tested in PCR and only 10 (17 %) samples were found positive.