<p>Radish (<i>Raphanus sativus</i> L.) is an important root vegetable utilized worldwide. Highly genetic diverse germplasm of radish exists in Sikkim, but no high-yielding and climate resilient cultivar has been released so far, causing hindrance in its productivity especially under organic conditions. The present investigation was conducted to assess the existing genetic variability, and yield potential along with phytochemical constituents of sixty-one entries (fifty-seven radish genotypes and four checks) using augmented RCBD to identify genotypic performance under organic cultivation. Presence of high phytochemical composition can help to identify radish as a functional food. In the present investigation, augmented RCB design helped to handle a large number of genotypes with limited replications. The traits like total carotenoid, total carbohydrate, total sugar, reducing sugar, antioxidant capacity and total phenol content showed strong genetic potential for further selection. Character association for biochemical traits revealed that many of the traits had strong influence on each other. The genotypes were grouped into eight sub clusters nested within two macro-clusters. The findings provide an important insight towards phytochemical constituents present and their genotype-by-environment interaction in tested radish genotypes. The study concludes that genotypes SR24, SR14, SR50 and SR42 were found to be superior for their biochemical composition while genotypes SR56, SR39, and SR41 were found to be superior across years for both yield and biochemical constituents. The investigation presents the possibility of selection for radish genotypes suitable for organic farming in Sikkim Himalayan region, alongside a valuable source of medicinal value and functional food properties.</p>