Two sequential coordinated experiments were carried out in order to find the lowest dose of the synthetic analogue of prostaglandin F 2α (Etiproston), capable of inducing parturition in the doe rabbit with efficacy, and to observe its effects on routine control of parturition and on some productive parameters in a year-long trial. 140 multiparous does of the California breed randomly allocated in seven groups of 20 animals were used in the first experiment, and injected on day 29 post-coitum (p.c.) with saline solution (Control), and 100 μg, 75 μg, 50 μg, 25 μg, 12.5 μg or 6.25 μg Etiproston at 10:00 h or at 16:00 h respectively. All doses of Etiproston significantly reduced the injection-parturition interval vs. Control, without differences in injection times, and also shortened the length of pregnancy by a mean of 22.6 h. The dose of 50 μg Etiproston showed a more regular effect on reducing the injection-parturition interval vs. other doses studied. A higher proportion of animals treated with Etiproston gave birth between 10:00 h on day 30 (p.c.) and 10:00 h on day 31 (p.c.) vs. Controls (94.0% vs. 55.0%, respectively). When 50 μg Etiproston was routinely administered in 25 does on day 29 (p.c.) at 10:00 h in the second experiment a significant decrease in variability or parturition time was also detected. 80.3% of does treated with Etiproston kindled between 24 to 46 h following treatment vs. 22.8% in Control animals. This effect was observed from the first to the eighth parturition. No influence on prolificacy and litter size at weaning were observed. Nevertheless, the no. born dead/litter decreased by almost 50% in does treated with Etiproston, and there seemed to be a tendency in that group to have a greater proportion of parturitions with no pups born dead. The results indicate that a small dose of Etiproston routinely administered on day 29 of pregnancy at 10:00 h, reduces birth-time variability and decreases neonatal mortality by almost 50% in the doe rabbit.