Good keeping quality (KQ) is a critical trait for sustaining potato cultivation under subtropical conditions, where post-harvest losses significantly impact profitability. To support breeding for improved KQ, a targeted evaluation of variability in key contributing traits was undertaken using a diverse germplasm set of 540 accessions of Solanum tuberosum ssp. tuberosum. The study utilized data from 2010 to 2020, incorporating control varieties Kufri Pukhraj, Kufri Dewa and Kufri Ashoka. Evaluation was performed using an augmented design with appropriate data transformations to mitigate annual environmental variations treated as block effects. The adjusted means revealed substantial phenotypic variation in sprouting (34.93%), firmness (20.77%), weight loss (27.32%), rottage (75.43%) and total weight loss (25.44%). Significant genotypic differences were observed for total weight loss and sprouting. Principal component analysis reduced data dimensionality, with the first three components accounting for 86.3% of the total variance. Biplots were generated using eigenvalues and eigenvectors to visualize the distribution of accessions based on KQ traits. Genotypes clustered in favourable zones on the biplots, enabling the identification of 18 superior keeping germplasm accessions: CP3151, CP3134, CP3117, CP3208, CP3211, CP3590, CP3515, CP3702, CP3336, CP3661, CP3514, CP4214, CP4229, CP4514, CP3588, CP3639, CP3795 and Kufri Dewa. The findings identify valuable parental material for breeding programs targeting improved post-harvest resilience in potato cultivars suited to the subtropical plains.