<p><strong>Background:</strong> Melasma is a chronic hyper pigmentary disorder mainly affecting females. It presents over the sun exposed areas of face. Various factors implicated in the etiology are sun exposure, pregnancy, OCPs, hormonal therapy, thyroid disorders, cosmetic use etc. The major causative factors are genetic predisposition and sun exposure. This study was aimed at studying the relation between duration of sun exposure and melasma development.</p><p><strong>Methods:</strong> 100 patients diagnosed with melasma were included. Detailed history was taken and clinical examination done. Modified MASI score was calculated. Patients were divided into four groups depending on hours of sun exposure. Data was collected in a proforma, tabulated and analyzed.</p><p><strong>Results:</strong> F: M ratio was 3.54:1 with 78% females and 22% males. 46% of females were in 4<sup>th</sup> decade and 72% of males were in their third decade. 35% of females were in 21-30 years age. Third decade was the commonest age of onset seen in 49% of patients. 46% patients had &lt;1 hour and 23% had &gt;6 hours of sun exposure per day. A p value of 0.0006 was found between the mMASI scores of group A and group D which was highly significant.</p><p><strong>Conclusions:</strong> More number of young males with melasma in their third decade are seeking treatment. Increase in the duration of exposure to solar radiation leads to more severe melasma. So, sun exposure is a major aggravating factor. There is a need to create awareness about sun protection.</p><p><strong> </strong></p>