This paper deals with the inaccuracy in results of the "Reliability constrained unit commitment with combined hydro and thermal generation embedded using self-learning group search optimizer proposed presented Energy 81 (2015) 245-254". The hydrothermal scheduling problem is defined as a non-convex optimization problem, which is necessary to meet several equality and inequality constraints such as power balance and technical limitations of cascaded and thermal hydro units. The driven solutions in the original paper do not satisfy the constraint on the final storage volume of the hydro units' reservoir one at the last hour. Therefor, this paper demonstrates this inaccuracy situated in the original paper. (C) 2015 Elsevier Ltd. All rights reserved.