This paper proposes an application of the Particle Swam Optimization technique to unit
commitment (UC) problem. In the proposed technique, the unit commitment is formulated as a
nonlmear optimization problem subject to the applicable constraints. A numerical comparison
between the results of the proposed technique and that of Dynamic Programming one has been
developed. This paper also represents a good contribution to the application of one of the modem
heuristic techniques in the power systems engineering area. The proposed solution methodology
has been validated and tested using known test system. The results obtained compared favorably
with those already available, thus showing the effectiveness and applicability of the Particle
Swarm Optimization technique for solving complex power system engineering problems.