Solving a problem is usually considered a sequential process, when one thought causes another one. Yet, many mental processes are concurrent. On the basis of modern ideas which suggest thinking may occur in a network consisting of similar but not identical elements functioning concurrently, we assumed concurrent processes also occur in problem solving. To test this theory, a special questionnaire and problem-solving tasks were used. Positive correlations between the results on the questionnaire and performance on the tasks may mean there is concurrent processing of information in problem-solving. Eight significant correlation coefficients were obtained out of ten possible. For the first time, it is shown that concurrent processes occur in problem-solving.