Background: Elderly people in the Philippines believe that extracts of watermelon seeds applied topically can heal oral thrushes. Citrullus lanatus (watermelon) has had various antimicrobial studies, particularly due to its rich linoleic acid content, which has a known antifungal activity. Candida albicans is one of the most common opportunistic pathogens, and it can cause candidiasis in different areas of the body: skin, nails, and mucous membranes. Objectives: This study aims to determine the antifungal activity of Citrullus lanatus (Watermelon) dried seed extract against Candida albicans by determination of the zones of inhibition produced by the said extract to the fungi. Methodology: In this study, a dried seed extract of Citrullus lanatus (Watermelon) was tested for in vitro antifungal activity by the Kirby- Bauer disk diffusion susceptibility test against a clinical isolate of Candida albicans. The zones of inhibition between the two trials were measured in millimeters (mm) and were then interpreted as to inactive, partially active, active and very active. Results: Two trials were conducted each consisting of 16 plates, all with 6 mm zone of inhibition and interpreted as inactive. Conclusion: Citrullus lanatus (Watermelon) dried seed extract did not show significant antifungal activity against Candida albicans using the disk diffusion method.