A parallel algorithm for constructing binary decision diagrams is described. The algorithms treats binary decision graphs as minimal finite automata. The automation for a Boolean fucntion with AND as its main operation (OR operation) is obtained by forming the intersection (union) of the regular sets associated with its operands. The union and intersection operations are implemented by a product construction on the minimal automata for the regular sets. After each product construction step the automaton must be reminimized. The parallel algorithm is designed so that it is possible to find the minimal representations for several Boolean operations in parallel. The level of each operation is determined. Operations at the same level can be performed in parallel without any communication between processors. If there are relatively few operations in one level, then the product generation step is divided into several suboperations and the results are merged.