The effects of several newly synthesized pyrazolo [4,3-d] pyrimidine-7-ones and pyrazolo-5-carboxamides on [3H]-flunitrazepam and [3H]-cyclohexyladenosine binding in rat cerebral cortex membranes have been studied. The compounds under examination, displaying affinities in the micromolar range for both benzodiazepine and adenosine A1 receptors, could be of interest in the study of a possible link between the two receptor systems.