The biological family Canidae is of great interest for scientists researching hybridization and speciation. The genus Canis appeared around 5 million years ago and all of its members have 78 chromosomes arranged in 39 pairs. Considering the fact that the reproductive isolation is not complete in younger evolutionary lines, members of different species can have fertile offspring - or hybrids. Because of anthropogenic influence, wolf-dog hybrids have appeared in the wild, which causes problems with the conservation of endangered species. Hybridizations have been reported between the domestic dog (C. familiaris) and grey wolf (C. lupus), coyote (C. latrans) and Ethiopian wolf (C. simensis). Among wild species, there have been reports of Eastern wolf-coyote (C.lycaon x C.latrans) hybrids, while the red wolf's status as a coyote-grey wolf hybrid is still questionable. While researching hybrids, a preliminary detection is neccesary using morphological characteristics, following an analysis of mtDNA, autosomal genetic markers and Y-chromosome genetic markers. Hybridization tends to be assymetrical, i.e. female wolves mating with male dogs and female coyotes mating with male wolves, although there have been cases of reverse combinations. This paper contains information about the most common hybrids in the wild, with emphasis on European and North American canid populations due to the fact there's an abundance of data from these two continents.