An experiment was conducted in sunlit, controlled environment chambers to determine effect of below-optimum temperatures on temporal trends of leaf net photosynthesis (A) and chlorophyll fluorescence (F) and on response to Ci and PAR of A and F of ‘Pensacola' bahiagrass (Paspalum notatum Flueggé). Five day/night temperature of 14/6, 18/10, 22/14, 26/18 and 30/22ºC were imposed from 55 to 100 days after transplanting for plants grown at 30/22ºC. Temporal trends of leaf A and F were measured during 10:00 and 14:00 h from -1 to 35 days from temperature treatment. Leaf A-F/Ci and A-F/PAR response curves were measured between 11 and 20 days after temperature treatment (DATT). Cold acclimation response of leaf Pn was assessed by lowering growth temperature in all treatments to 6ºC and measuring A and F for 3 days from 36 to 38 DATT. Repeated measures analysis of temporal trends showed significant effects of time, temperature and time x temperature. Decrease in growth temperature significantly reduced CO2-saturated net photosynthesis (Asat), PEPC efficiency and electron transport rate (ETR) derived from A-F/Ci curves. Decrease in temperature also reduced light-saturated photosynthesis (Amax), Rd and ETR derived from A-F/PAR curves. Relationships between various leaf level A and F parameters at below-optimum temperatures will be discussed.