Background: Nowadays, musculoskeletal ailments are not unusual amongst dentists. Excess body weight and lack of practising ergonomic principles in their practice could also have an additive effect. Aim: This scientific research intends to determine the association between body mass index and ergonomics-related musculoskeletal disorders among privately practising dentists at Saidapet Neighbourhood of Chennai city, Tamilnadu, India. Materials and Method: A cross-sectional study was directed among 117 dental surgeons practising at Saidapetneighbourhood of the Mambalam taluk, Chennai city, Tamil Nadu, India. The multistage cluster sampling technique was employed to designate the study population. The Quetelet index was subsequently used to record each participant's height and body weight. A previously validated (as per the Canadian Center for Occupational Health and Safety- CCOHS) questionnaire consisting of 12 open-ended and closed-ended questions was utilized to obtain information regarding demographics, work information, symptoms, and causes of musculoskeletal pain. Statistical analysis was done using descriptive statistics and the Chi-square significance test. A probability density value ( p-value ) less than 0.05 was considered statistically significant. Results: There were positive correlations not only between the body mass index and the number of years of private dental practice (P value < 0.02) but also between the degree of interference of their musculoskeletal pain with their performance at clinics (P value <0.04) and interference of their musculoskeletal pain after work (P value <0.01). Conclusion: Abnormal body mass index was also an additional causative factor for ergonomics associated musculoskeletal disorders. Thus, dentists must abide by the ergonomic principles and the OSHA (Occupational Safety and Health Administration) guidelines while keeping an eye on their body weight and personal health.