<p>Salinity stress is one of the important abiotic stresses adversely affecting agricultural productivity worldwide, including common bean (<i>Phaseolus vulgaris</i> L.). This study screened for the physiological responses of 30 common bean lines grown in Malawi under salinity conditions. The study involved three consecutive experiments. The first experiment was focused on morphological responses of 30 common bean lines to salinity. For the second experiment, 12 common bean lines that were selected from the first experiment were evaluated for stress tolerance index (STI) and stress susceptibility index (SSI). Based on this study, two tolerant (Kha 47 and 71) and one sensitive (MCT 10) lines were identified. Kha 47 and 71 showed lower specific leaf area (SLA) and leaf area ratio (LAR) under salinity stress as compared to line MCT 10. Both tolerant common bean lines exhibited higher membrane integrity, total soluble sugars and leaf relative water content. Saline tolerant common bean lines showed selective ion uptake, having high K⁺/Na⁺ ratio than sensitive one. Photosynthetic efficiency in terms of Fv’/Fm’, φNRED, φPSII, lower φNPQ and NPQ was higher than the sensitive line. The findings of the study revealed that salinity tolerance in the tolerant common bean lines is dependent on the regulation of root and leaf Na⁺, accumulation of both organic and inorganic solutes and maintenance of higher photosynthetic efficiency.</p>