The Salda Lake basin which is in the southwestern Turkey is an important water body in view of environmental values. We used stable isotopes (delta D and delta O-18), delta H-3 and C-14 composition of the water samples to understand recharge process effective in the groundwater and lake water. Water samples were collected in dry and wet periods and the stable isotope (delta D and delta O-18) and radiogenic isotope (C-14) analysis were made in the basin. The delta O-18 contents of groundwater and lake water ranged from -9,94 parts per thousand to 1,18 parts per thousand in dry period and from -10,24 parts per thousand to 0,30 parts per thousand, in wet period. delta D contents of groundwater and lake water varied from -67,42 parts per thousand to 1,20 parts per thousand and from -64,51 to -2,80 parts per thousand, in dry and period wet respectively. The stable isotope data of samples indicate a meteoric origin for all samples. According to stable isotope data, groundwater samples seem to be recharged from higher elevations whereas the lake water is recharged from low elevations. The tritium (delta H-3) content of the water samples ranges from 1.04 to 4.49 TU and from 1.91 to 4.18 TU in the dry period and wet period respectively. Long-term delta H-3 observations are required to determine whether these delta H-3 signals are associated with young recharge or with the groundwater with long residence time. In addition, the C-14 activities of the samples vary between 90 pmc and 110 pmc for Salda Lake waters and 530 pmc and 5990 pmc for the groundwater.