Investigations were carried out to study the physiological and yield variability in sunflower lines at college farm, College of Agriculture, PJTSAU, Hyderabad during late rabi 2013-14. The material composed of four sunflower hybrids (GMU-337, GMU-437, EC-602063 and DRSF-113). Water stress imposed from 30-65 DAS resulted in decreased SCMR values, stomatal conductance, fluorescence, and photosynthetic rate. The analysis of variance revealed the presence of sufficient variability for physiological attributes. The genotype DRSF-113 showed maximum values for SPAD chlorophyll meter readings (31.5), stomatal conductance (193.5 mmol (H2O) m-2 s-1), photosynthetic rate (25.5 ? moles CO2 m-2s-1), fluorescence (Fv/ Fm) (0.565) and yield (1488 kg/ha) . The results also shown that the yield positively correlated with leaf greenness (SPAD chlorophyll meter readings) and fluorescence (Fv/ Fm). Based on the results, out of the four genotypes studied DRSF-113 and EC-602063 can be concluded as tolerant for moisture stress than genotypes GMU-337 and GMU-437.