In order to examine the effects of saline water (0.2, 1.5, 4.0, 6.5 and 9.0 dS·m-1) without or with plastic mulch (black or green infrared transmitting) on the physiology and yield of bell peppers (Capsicum annuum L. var. Red Night), plants were drip irrigated and grown in greenhouse conditions. Salinity did not significantly decrease the rate of photosynthesis until fruit set after which irrigation with 6.5 and 9.0 dS·m-1 reduced rates by 35%-38% and during fruit development by 50% compared with the control treatment. Plants receiving 4.0 dS·m-1 had significantly lower (30%) photosynthetic rates than the control during fruit development. Stomatal conductance decreased as the rate of salinity increased which in turn affected transpiration. No consistent differences in photosynthesis, stomatal conductance and transpiration rates were obtained with or without plastic mulch. The marketable yield was negatively affected as salinity increased having being reduced by 17%, 64%, 96%, and 100% for saline treatments compared with the control. The number of fruit of fruit per plant was significantly lower at rates of 4.0 dS·m-1 or higher. No significant differences were detected among plastic mulches and non-mulch condition in marketable yield and number of fruits. Water consumption decreased as salinity level increased with decreases of 11%, 20%, 38%, and 52% of the control value. Mulching the soil reduced water consumption by 30% compared with bare soil.