Studies have shown that toxicological analysis by liquid chromatography is more sensitive when using insect larvae rather than body tissue. This increases the importance of using insects in this type of research and investigation. Parathion (C10H14NO5PS) is an insecticide and acaricide widely used in agriculture. In the current study, three rabbits were given a lethal dose of parathion by intracardiac injection, and a fourth was killed by cervical dislocation. Samples of liver were taken from each rabbit to certify the presence of parathion in the tissue. A high concentration of parathion was found. The study was conducted in urban conditions in a university in Colombia. Samples for the study of insect succession were collected over a period of 28 days, three times a day for the first 12 days, two times per day for the next 3 days, and once a day for the last 12 days. The presence of parathion only repelled arthropods or had insecticidal effects at the mouth of the treated rabbits. No relevant differences in insect succession were found between the four rabbits. HPLC was found to be an efficient technique for detecting and quantifying parathion in tissues as well as in arthropods present from the initial to the final stages of decomposition, including dry remains. 3 tables and 31 references