<p><em>&nbsp;</em></p>
<p><strong><em>SUMMARY</em></strong></p>
<p>In recent times there has been a high increase in the intensification of the productive systems of tilapia(oreochromis niloticus) causing physiological alterations in fish due to stress levels, stimulanting the development of new diseases such as those caused by the presence of different organims, even more from streptococcus agalactiae, a gram positive bacterium that generates mass mortality. This article describes a clinical case of streptococcus agalactiae in silver tilapia in a fattening lake on land in the municipality of hobo, department og Huila. The tilapia revealed different clinical sings in which skin lacerations were found, exophthalmia in most cases and the presence of erratic swimming associated with the presence of streptococus agalactiae given a mortality of 1178 tilapia, 10 tilapia were taken, histopathological samples were taken, a pool of affected organs and a PCR teste were carried out.the presence of streptococus agalactiae was confirmed. The presence of this disease is attributed to a high level of organic matter in the lake as well as a high carrying capacity, which helps to spread the disease affecting many more individuals generating economic losses in intensive production.</p>
<p>&nbsp;</p>
<p><strong>Key words</strong>: Fattening, Streptococcus agalactiae, seeding, silver tilapia, Oreochromis niloticus.</p>