Phytoseiid mite diversity was surveyed on wild and cultivated plants in Morocco and Tunisia from 1994 to 2003. Results were associated with those obtained in previous surveys conducted by other authors in Algeria and in one of the Canary Islands (Gran Canaria). They showed, 21 species are known from Tunisia (1 was known before), 53 from Algeria, 41 from Morocco (15 were known before) and 23 from the Canary Island. Eight were known from all these islands before the data published in 2003 concerning only Gran Canaria, which represent a very small area compared to the three large countries, above all to Algeria. Ten species were common to all the four countries, 4 to Morocco, Algeria and Tunisia, 1 to Algeria and Tunisia. One species was in Tunisia and Morocco, suggesting that this species might also be present in Algeria, 1 was present in Morocco, Algeria and in the Canary Island. Nine species were found in Algeria and Morocco and one species in Algeria and the Canary Island. The authors detected a new genus and a new species in Tunisia, 8 new species in Morocco, and published data mentioned 6 new species in the Canary Island. The considerations on biogeography were also given.