Contextualization: To guarantee the quality of the water in the reservoirs destined to the treatment and supply of drinking water, toxicity analyzes of the water and sediments must be carried out periodically, due to its can be reservoirs of the organic pollutants that during remobilization processes could make those available in the aquatic ecosystems.   Knowledge gap: Because these contaminants concentrations are found in traces (ng/L), it is necessary to use passive sampling methods that allow the accumulation of hydrophobic compounds in semi-permeable membrane devices (SPMDs) for subsequent evaluation.   Purpose: The purpose of this study was to evaluate the toxicity of samples from SPMD-type passive sampling extracts and sediments by the use Microtox® assays using the Vibrio fischeri bacteria.   Methodology: The 24 extracts used in the trial were obtained from semi-permeable membrane devices (SPMDs) previously deployed for 21 days in 6 stations located in the reservoir of the La Fe, Antioquia, in four sampling campaigns. The extracts were tested by Microtox Basic Test medium. The evaluation of the toxicity potential of the reservoir sediment was also analyzed by means of acute toxicity tests with Microtox® applying the Solid Phase Test (SPT) protocol as well as the physicochemical parameters of water such as pH, temperature, electrical conductivity, dissolved oxygen and turbidity.   Results and conclusions: The results of the toxicity tests indicate that the analysis of the extracts of SPMD collected in water reservoir La Fe does not present toxicity, while those fed by sediments presented moderate or low toxicity.