A performance analysis of an OTEC plant using an integrated hybrid cycle (I–H OTEC Cycle) has been conducted. The I–H OTEC cycle is a combination of a closed-cycle OTEC plant and a spray flash desalination plant. In an I–H OTEC cycle, warm sea water evaporates the liquid ammonia in the OTEC evaporator, then enters the flash chamber and evaporates itself. The evaporated steam enters the desalination condenser and is condensed by the cold sea water passed through the OTEC condenser. The optimization of the I–H OTEC cycle is analyzed by the method of steepest descent. The total heat transfer area of heat exchangers per net power is used as an objective function. Numerical results are reported for a 10 MW I–H OTEC cycle with plate-type heat exchangers and ammonia as working fluid. The results are compared with those of a joint hybrid OTEC cycle (J–H OTEC Cycle).