The presence of alloctone bacteria isconsidered as one of the more important biological pollutants of water bodies, existing one close relation between the fecal contamination indicators and the existence of urban and industrial zones. In the present study we utilized indicators of fecal contamination (coliforms and streptococci) and the coliform/streptococci index (FC/FE) for determine the origin of fecal pollution in two water bodies of Temuco, Northern Campus at north surrounding of Temuco, and Rucamanque source that is located in a rural zone. It utilized the multiple assays number for obtain the bacteria more probable number in 100 mi of water sample. It was done the correlations between microbiological indicators and physic-chemical variables. The results indicate that both sites have low fecal contamination. It was reported important correlation between fecal coliforms, temperature and pH, but negative correlations with dissolved oxygen. The index (FC/FE) was correlated only with dissolved oxygen. The temperature would have an important regulator role in the coliform growth, whereas the fecal streptococci have high densities at low values of temperature, conductivity and dissolved oxygen. The origin of microbiological pollution was related with the antrophogenic intervention in both studied sited, human origin in Northern Campus, and mixed origin in Rucamanque source. It was suggest the use of index as first approach for identify the origin of fecal pollution.