Chickpea, a cool-season grain legume enriched with high nutritive value is grown globally over 90 countries. Seed weight trait is one of the important quality parameters for fetching premium market price. Thus, improving seed traits, including high 100-seed weight (SW) is one of the major targets of chickpea breeding. A study of genetic variability, molecular diversity and marker-trait association (MTA) analysis for 100 SW was performed in a panel of 96 chickpea genotypes consisting of crop wild relatives, landraces, advanced breeding lines and released varieties. A wide range of genetic variability and high heritability for the studied trait indicated the great scope of improving this trait. Simple sequence repeat marker-based genetic diversity analysis grouped all the genotypes into two groups. This result was consistent with the result obtained from factorial and population structure analysis. To delineate the significant marker-trait association for 100 SW, association analysis was performed in the given panel of chickpea genotypes. The mixed linear model (MLM) was employed for detecting significant MTAs for 100 SW. Following MLM analysis, a total of seven significant MTAs was detected in the year 2016-17. While in the year 2017-18, MLM analysis showed three significant MTAs for 100 SW. Three markers TAA60, CakTpSSR02719, H1B04 markers exhibited significant MTA for both the years consistently. Thus, these genomic regions could be fine mapped in future for improving 100 SW in chickpea.