Background: The term interstitial lung diseases (ILD) refer to a broad category of lung diseases rather than a specific disease entity. True prevalence of ILD is difficult to estimate and it may vary according to the geography, environment, occupation etc. Aim and objectives were to find out the distribution of interstitial lung disease (ILD) subtypes in a tertiary care centre. Methods: A descriptive study was conducted between August 2016 and November 2018 in a tertiary care centre in Puducherry, South India. Baseline demographic details, clinical symptoms, signs, radiological findings (chest radiograph and HRCT), pathological findings, and physiological findings were taken into consideration and diagnosis of type of interstitial lung disease was made using multidisciplinary discussion. Statistical analysis was done using SPSS 19.0 version.Results: A total of 150 patients were recruited of which 70.5% were females. Most common ILD subtype in our study was connective tissue disease associated ILD – 97 patients (65%) followed by idiopathic pulmonary fibrosis (IPF)–31 patients (22%). Most common type of CTD ILD observed in our study was progressive systemic sclerosis (46%) followed by mixed connective tissue disease (24%). The most common HRCT finding was NSIP pattern and most commonly observed physiological abnormality was moderate restriction and moderate diffusion impairment. Conclusions: Connective tissue disease-associated ILD was the most common ILD found in our study amongst south Indian population. This suggests that the distribution of ILD would vary depending on the geographical area and the environmental exposure which was in contrast with the Indian ILD registry.