Circadian rhythm of body temperature was tested in summertime on a group of 16 N.Z.W. rabbits (8 bucks and 8 does) aged 10 weeks. The results showed a two-wave trend with a major peak at 16.00 (40.6 + or - 0.2) and a minor one at 06.00-08.00 (39.7 + or - 0.2ºC). The minimum was observed at 10.00 and 22.00-02.00 and was 39.7 + or - 0.3ºC and 39.5 + or - 0.2ºC respectively. The comparison with data from literature shows that the day-time wave is an effect of perturbation induced by ambient temperature, while the peak in the early morning can be related to metabolic activity. The comparison with experimental data collected in Egypt, in similar ambient conditions, suggests that North African rabbits have developed a better resistance to heat stress.