Introduction: The world’s biggest industrial disaster causes due to the leakage of MIC in Bhopal, India, on 3 Dec. 1984 led to the death of about 2000 people within 72 hours. Exposure to toxic gases resulted in morbidities in survivors, especially affecting the respiratory system. The objective of this study was to assess the temporal trend of morbidities in the gas-exposed survivors in Bhopal and its relationship with grades of exposure. Methods: Based on mortality rates during the first 3 days after the accident, the gas-exposed area was divided into severely, moderately and mildly affected. A long-term follow-up epidemiological study was launched in 1985 after assembling a cohort of 80,021 gas-exposed and 15,931 unexposed subjects. Both cohorts were followed up at a six-month interval and morbidities were recorded in a structured verbal autopsy questionnaire. Data presented here collected up to 2010. Results: During the acute stage in December 1984, 98-99% exposed subjects in the affected areas suffered from various morbidities. In 2010, all cause morbidities rates were 22%, 17% and 17% in severely, moderately, mildly affected areas, respectively, compared to 8% in the unexposed area. Time-trend analysis revealed that all cause morbidities in the exposed cohort have nearly attained a plateau since 1991, and have consistently been higher than in the non-exposed cohort (p<0.001). Higher prevalence of all cause morbidities was observed in people above 45 years of age in the exposed cohort, who were young adults at the time of the accident. Respiratory causes have been the main reason of mortalities in the exposed cohort, fluctuating between 40-57% in the affected areas and 17-34% in the control area (p=0.01). Conclusions: Exposure to toxic gas fumes has resulted in an increased prevalence of all cause morbidities in the exposed population of Bhopal, remaining several times higher than in the unexposed population even 25 years after the accident.