[en] The results obtained during the first stage of an experimental program on the study of plasma focus neutron emission are presented. The measurements were performed on two plasma focus devices having maximum stored energies of 4 kJoule and 20 kJoule, respectively. By carrying out correlated measurements on the neutron emission (using scintillator-photomultiplier and Geiger-Muller counters), on the hard X-ray emission and on the discharge current, some conclusions regarding the possible mechanism responsible for the neutron emission in these devices have been drawn. Neutron energies in the range 1.5-3 MeV have been determined; typical neutron yields are 10⁶ neutrons/pulse (at 3.2 kJoule) and 10⁸ neutrons/pulse (at 10 kJ) for the two devices operating in deuterium. (author)