In order to replace the PMSG treatment used for oes trus ynchronisation, the effects of the increased lighting from 8 to 16 hours were examined. The expe rim nt was carried out at the University of Kaposvár using Pannon White rabbit does. Prior to t he experiment does were kept using a 16L:8D lighting program and each doe had 2-3 parturitions. The does were randomly housed in two identical rooms. Rooms differed only in lighting regime. In t he first room a 16L:8D lighting regime was used throughout the experiment (16-16L group). In the ot her room a lighting system of 8L:16D was used during the days (lighting: between 6.00 and 14.00) after parturition, then the light period was increa s d to 16 hours per day 8 days prior to insemination (l ighting: between 6.00 and 22.00). After insemination the lighting period was modified to 8 hours per day (8-16L group). Light intensity measured in the cages at the height of rabbit does ranged between 40 and 70 lux. In the 16-16L and 816L groups, 153 and 154 inseminations (94 and 111 p arturitions) of 55 and 54 rabbit does were evaluated, respectively. Based on the results, the increased lighting period prior to insemination favourably affected pregnancy rate (16-16L: 61.4% v s. 8-16L: 72.0%, P<0.05). Although the differences were not significant, number of kits bo rn alive and litter size at 3 weeks of age were hig her in the 8-16L group, while slightly higher individua l nd litter weights were recorded at the age of th ree weeks in the 16-16L group. No differences were foun d for mortality between the groups. Comparing the pooled results per 100 inseminations, the 8-16L does produced 16% more kits alive at birth (620 vs. 522, P<0.05). Light stimulation could be an alt ernative to PMSG treatments. Nevertheless, further experiments will be necessary to determine the caus e of the decreased rabbit weight when applying longer daily lighting program and to test the durab ility of the positive effects.