Introduction: Some of the patients on re–treatment regimen of RNTCP for Pulmonary tuberculosis may have multi drug resistant TB (MDR–TB). Patient’s profile and previous treatment history may provide hints as to who are most likely to have MDR–TB. Aims and Objectives:The aim of study was to determine risk factors which might predict possibility of having Multidrug resistance, in the pulmonary Tuberculosis patients before starting them on re–treatment regimen of Revised National Tuberculosis Control Programme (RNTCP). Material and Methods The study was a prospective case control study conducted for one year from 01^st April 2007 at Lala Ram Sarup Institute of Tuberculosis and Respiratory Diseases, New Delhi. Twenty MDR–TB patients in the case group and forty patients matched by age, sex and subtype of re–treatment regimen were enrolled in the control group. Patient’s demographical, clinical, bacteriological, and radiological profile was recorded. Conclusions Statistically significant risk factors for  Multidrug resistance were Prior history of Anti Tuberculosis T/T more than twice, Prior TB treatment for more than 11 months, presence of cavitation, bilateral and far advanced disease on the chest radiograph. Factors like smoking, alcoholism and treatment interruptions were not associated with development of MDR–TB.