In this paper, the particle swarm optimization technique with constriction factor is proposed to solve short term multi chain hydrothermal scheduling problem with non smooth fuel cost objective functions. The performance of the proposed algorithm is demonstrated on hydrothermal test system comprising of three thermal units and four hydro power plants. A wide range of thermal and hydraulic constraints such as power balance constraint, minimum and maximum limits of hydro and thermal units, water discharge rate limits, reservoir volume limits, initial and end reservoir storage volume constraint and water dynamic balance constraint are taken into consideration. The simulation results of the proposed technique are compared with those obtained from other methods such as, simulated annealing (SA) and evolutionary programming (EP) to reveal the validity and verify the feasibility of the proposed method. The test results show that the proposed algorithm achieves qualitative solution with less computational time when compared to the other methods.