This study was carried out in Ague river, La Mesa District, Province of Veraguas. The main purpose of this research was to determine the families and genera of aquatic insects. Six stations were located along the river. These ones were collected twice a month in the morning from Febrary to August 2002. The samples were collected in a period of one hour per station where the capture methods varied in accord to the sustrate. In addition, we used an aquatic net (D-Net) in order to sweep the botton of the river and sumerged marginal vegetation. Besides, the insects located in the muddy-rocky substrate were removed with the help of entomological pincers. As a result, we obtain 81 genera of aquatic insects distributed in 50 families and 10 orders. Hemiptera was the best represented with 22 genera and 10 families. By other insects were distributed as follow: Odonata with 20 genera and 8 families; Coleoptera 13 genera and 12 families; Ephemeroptera with 11 genera and 6 families; Trichoptera 13 genera and 7 families; Diptera with 3 genera and 3 families, while Lepidoptera, Plecoptera, Neuroptera and Blattaria were represented by one genus and one family.