Water quality parameters of Kaj and Sendegan rivers in Chaharmahal and Bakhtiari province were assessed for rainbow trout culture. For Kaj and Sendegan rivers, 6 and 5 sampling stations were selected, respectively. The water samples were collected once a month from May to October (2015) and were sent to laboratory for assessing: Nitrite, Ammonium, Soluble Phosphate, BOD₅, COD, TSS, TDS, Cu, Zn, Hg, Cl^-, organophosphate toxins, pH, Malachite green and EC. The Nitrite concentration in Sendegan River (0.106 mg/l) was equal to standard (p>0.05) and in Kaj River (0.079 mg/l) was lower than standard (p<0.009). The soluble Phosphate concentration was higher than standard (p<0.0007) in the studied rivers (0.162 and 0.152 mg/l for Kaj and Sendegan, respectively). Measured TDS for Kaj (225 mg/l) and Sendegan (335 mg/l) rivers were higher than standard (p<0.03 and P<0.0001, respectively). BOD₅ and COD concentrations were lower (p<0.0001) than its standards for two rivers (2.67 and 5.56 mg/l for Kaj River and 2.16 and 4.22 mg/l for Sendegan River, respectively). Amount of Malachite green in the last station of Kaj River was 0.003 mg/l (p>0.05) and in the last station of Sendegan River was 0.065 mg/l (p<0.05). The EC of Sendegan River (562 µs/cm) was higher than standard (p<0.0003). Other parameters in the both rivers, were lower than the standard (p<0.0001). Generally, water quality of Kaj and Sendegan rivers were not suitable for rainbow trout culture.