Cumin is the largest grown seed spice (7.14 lakh ha) and second largest grown spice next only to chilli (8.44 lakh ha) in India during 2022-23. The yield of cumin in India is 647 kgha-1; varies from district to district in Rajasthan (424 kgha-1) and Gujarat (995 kgha-1). Yield difference in Gujarat and Rajasthan needs to measure to assess the existing yield gap (YG), factors responsible and appropriated remedial measures. The present study has tied to document this YG during 2006-07 to 2021-22 with possible reasons. In Rajasthan, study measures a YG of 23% (115kgha-1) at state level. In major cumin growing districts namely, Barmer (43%), Jaisalmer (31%), Pali (21%) and Jalore (21%) had YG of 214, 153,107 and 106 kgha-1 respectively, over Nagaur during TE 2020-21. In Gujarat, at state level a YG of 17% (162 kgha-1) is found. Over Kutch, highest YG of 43% (417kgha-1) is measured in Patan district, followed by Jamnagar (35%). Surendranagar, the largest cumin growing district of Gujarat, harvested 27% (264 kgha-1) lower yield than Kutch. Changes in climate, soil health, crop management, inputs use, extension services, farm mechanization, and post-harvest management etc. are main yield determining factors in a particular district. If the yield of the aforementioned major cumin-growing districts improves by 25% over the next five to six years, the country's current cumin acreage will yield an additional thirty-five thousand tons of cumin.