Organizations are increasingly faced with the challenge of managing business processes, workflows, and, recently, Web processes. One important aspect of processes that has been overlooked is their complexity. High complexity in processes may result in bad understandability, errors, defects, and exceptions leading processes to need more time to develop, test, and maintain. Therefore, excessive complexity should be avoided. This paper describes an experiment designed to validate the Control-Flow Complexity (CFC) metric that we have proposed in our previous work. In order to demonstrate that our CFC metric serves the purpose it was defined for, we have carried out an empirical validation by means of a controlled experiment. The explanation of the steps followed to do the experiment, the results, and the conclusions obtained are the main objectives of this paper.