Efficient task scheduling of computationally intensive applications is one of the most essential and difficult issues when aiming at high performance in heterogeneous computing environments. Although a large number of scheduling heuristics have been presented in the literature, most of them target only homogeneous computing systems. In this paper we present a simple list-scheduling heuristic for a bounded number of heterogeneous machines called Heterogenous Critical Parent Trees (HCPT). The analysis and experiments have shown that HCPT provides comparable or even better results together with low complexity.