In this work, the boiling heat transfer behaviour of a particular nanofluid, namely water-Al₂O₃ mixture, has been investigated. The results, expressed in terms of surface heat flux q_S'' as function of excess temperature ΔT_e, have shown that the presence of particles has a drastic impact on the boiling behaviour of the nanofluid studied. Within the nucleate boiling regime, it has been observed that, in general, the increase of q_S'' with respect to ΔT_e appears clearly less pronounced than that of the distilled water; also, the surface heat flux decreases appreciably with an augmentation of particle concentration. For sufficiently high excess temperature, q_S'' tends to become constant. It has also been observed that the peak surface heat flux in nucleate boiling, q_S,max'' , has clearly decreased with an augmentation of particle concentration; such a decrease has been found to be as high as 65% for a 2% nanofluid, which is believed to be due to a certain deterioration of the particles dispersion properties under the effect of high temperature.