The contribution of one major or a combination of several physiological processes in salt tolerance was assessed in three local varieties (Blacklong, Advanta-1103, and Dilpasand) of ridge gourd Luffa acutangula (L.) Roxb. at varying salt levels (0, 75, and 150 mM NaCl). Based on growth attributes, var. Dilpasand as salt-tolerant and var. Blacklong as moderately salt-tolerant, while var. Advanta-1103 as salt-sensitive. Inter-varietal differences for photosynthetic pigments and relative water content (RWC) was not observed. The salt-sensitive variety Advanta 1103 had greater Na+ accumulation (73.72%) in the leaves than those in the moderately tolerant and tolerant varieties. Total soluble proteins were relatively lower (58.25%) in the salt-sensitive variety but maximal increase (69.34%) in total free amino acids was observed. However, accumulation of proline was maximal in the salt-tolerant variety (Dilpasand). Salt-tolerant variety exhibited minimal oxidative stress (relative low levels of H2O2) and membrane damage (low content of MDA and electrolytic leakage) and higher activities of antioxidant enzymes (catalase and peroxidase). Although all ridge gourd varieties down-regulated the electron transport through PSII by increasing the safe dissipation of heat Y(NPQ) to lower the ROS generation, this was maximal in the salt-tolerant variety Dilpasand. Relatively greater reduction in Y(ND) and enhancement in Y(NA) indicated PSI-photoinhibition in salt-sensitive variety. The greater salt tolerance in var. Dilpasand was due to the coordinated impact of ion exclusion, higher accumulation of proline, better capacity to manage electron transport from PSII to PSI with higher Y(NPQ) and antioxidant capacity. •Considerable intra-specific variability for salt tolerance in a small set of germplasm of ridge gourd has been found.•Degree of salt tolerance in ridge gourd varieties was associated with ion exclusion, proline accumulation, antioxidant potential and efficiency of photosystem II.•Salt tolerant variety Dilpasand had better ability to protect PSII by down-regulating electron transport and up-regulating Y(NPQ).•Quantum yield of PSII and Y(NPQ) are positively correlated with MDA, activities of CAT and POD, Na+ accumulation, and proline accumulation.•Quantum yield of PSII and Y(NPQ) can be used as potential indicators of salt tolerance in ridge gourd.