During the last decades there has been an increasing interest in artificial insemination in the dog. The inseminationof a bitch can be performed using fresh, chilled or frozen-thawed semen. Sperm can be inseminated in the vaginaby using a plastic insemination device or by the Osiris catheter. Intra-uterine insemination can be performed bymeans of laparotomy which is ethically controversial and prohibited in several countries. Better techniques for intra-uterine insemination are the transcervical catheter or the insemination of a catheter under endoscopic visualization.Intra-uterine insemination results in higher whelping rates for fresh, chilled and frozen-thawed semen than intravaginaldeposition and additionally results in higher litter sizes when frozen-thawed semen is used.