Aim: The present study was designed to investigate the anterior and overall tooth size discrepancy in patients seeking orthodontic treatment irrespective of the malocclusion in the South Trivandrum population. Materials and methods: Good quality study models of both maxillary and mandibular arch of 55 subjects from the age of 13–30 years were selected randomly irrespective of malocclusion. A digital Vernier caliper was used to measure the mesiodistal tooth width. Bolton's anterior ratio and overall ratio were determined. Results: For the present study descriptive statistical analysis is being used. A clinically significant anterior discrepancy was found in only one-third, while the overall discrepancy was encountered in almost two-thirds of our sample. 69.1 and 32.7% of the sample had higher anterior and overall ratios, respectively compared to Bolton's ratio indicating larger mandibular tooth size. Conclusion: Mandibular anterior excess was found in more than double the subjects with maxillary excess. Clinicians should be aware of this discrepancy that may influence orthodontic treatment goals and outcomes substantially. Thus, the Bolton tooth-size index must be a primordial tool in the quotidian orthodontic diagnosis process and treatment planning. Clinical significance: Orthodontic treatment may vary from patient to patient but once we reach the finishing stage, it's almost similar in most of the cases. In pursuit of achieving an ideal and optimal occlusion, the orthodontic community has always looked to the six keys of normal occlusion laid down by Andrews. Unfortunately, tooth size imbalances were not critically looked at by Andrews prompting McLaughlin and Bennett to include a seventh key to address the issue of tooth size imbalances.