A survey of the aquatic Heteroptera was made in lotic and lentic systems in the Quindio department, Colombia, over the months of April to October 2005. A total of 3,355 specimens were collected belonging to 13 families, 27 genera and 53 species. Gerromorpha was the most diverse suborder with 28 species (52%) and Nepomorpha was the second with 25 species, which represented 47% of the total collection. For the department 42 new species are registered and for the country nine. The genera Buenoa (Notonectidae) and Rhagovelia (Veliidae) were the best represented (11,3%) with six species each. Rhagovelia cauca was the most abundant species in all of the survey; the high frequency of encounter of this species could be due to its wide altitudinal distribution. Low diversity values were found at higher altitudes, which could be due to the altitudinal limit of species, whereas the physical and chemical parameters showed values that allow aquatic life, yielding a high richness of individuals at the 104 sample stations. The distribution of Nepomorpha species was related to the physiochemical characteristics of the water while Gerromorpha species were mainly related to the type of body of water.
