In medicine, the importance of mites in house dust gains importance from day to day. The close relation between these arthropods and man is the cause of a series of health problems such as allergic asthma, rhinitis and/or dermatitis. House dust samples were collected between January and December 1991 in Punta Arenas, city, Chile. Samples were processed by the <A HREF="#Artigas 1983">Artigas and Casanueva (1983)</A> technique, modified by Muñoz et al. (1983). The isolated specimens were subsequently identified using the <A HREF="#Artigas 1983">Artigas and Casnueva (1983)</A> pictorial key. Of the 134 samples studie, 29.1% presented one or more mite species. A total of 13 species were classified. Eight of them were registered for the city of Punta Arenas for the first time. Average weight of the dust analysed was 8.4 g. Mites were found from 0.2 g. onwards. A total of 1768 specimens was collected. The species more representative were: Blomia tjibodas (30.1%), Glycyphagus destructor (22.5%) and Tyrophagus putrescentiae (10.8%). The seasons that presented the higher proportions of mites were autumm (39.4%) and spring (37.1%).