The present paper investigates the performance of a conventional single slope passive solar still (CSS) under the influence of a paraffin based phase change material (PCM) and a nano-PCM (n-PCM) in terms of the fresh water production per day. To achieve this objective, three solar stills with the same dimensions were designed and fabricated. Among them, one still was left without any modification (CSS), another one was incorporated with paraffin as PCM (PCMSS), and third one was assimilated with an n-PCM (NPCMSS). Previously, the n-PCM was prepared by adding 0.5% mass of silica nanoparticles in paraffin. The experiments had steered on a hot and humid weather at Coimbatore, India during the month of April 2020. The results evidenced that the incorporation of PCM and n-PCM improved the fresh water production by 51.22% and 67.07%, respectively.