We present the experimenal results on the formation of zinc oxide nanoclusters during the ablation of sintered ZnO targets by a pulsed ArF laser both in vacuum and in the controlled gas atmosphere (helium and/or oxygen). Even in vacuum, the small clusters have been detected by time-of-flight mass-spectrometry. The presence of the surrounding gas favors the synthesis and growth of the clusters. The initial cluster ions play a role of condensation centers for the further cluster growth up to sizes of several nanometers. The evolution of the laser-induced plasma plume has been monitored by iCCD imaging and by time resolved optical spectroscopy. The radiation emitted by plasma is due mainly to atomic transition of neutral Zn. In the case of ablation in oxygen, the dynamics of plume expansion is strongly influenced by chemical reactions between the ablated particles and surrounding gas molecules. Under laser excitation, we have observed the photoluminescence (PL) of the gassuspended clusters. An intense PL band centred at the photon energy of 3.27 eV has been attributed to the radiative recombination of free excitons in crystalline ZnO at the room temperature. This result indicates that the nanoclusters are already cooled and crystallized in the gas suspension.