Organophosphourus (OP) chemicals were broadly used as insecticides and in the treatment of human diseases such as the malaria mosquitoes, parasitosis, myasthenia, and glaucoma. The OP toxicity is well known, they can cause environmental and health problems and the possibility to accumulate in the food chain. The acceptable daily intake (ADI) can be considered as a measure of the effect of pesticide residues in food on human health. In this paper the partial least squares (PLS) approach is used to evaluate the ADIs (expressed as pADIs) of a series of 46 structurally diverse OPs. OP structures were pre-optimized using the MMFF94s force field and structural descriptors were calculated for the minimum energy conformers. This dataset was divided into 26 training compounds, and 20 pesticides were included in the prediction set. Several criteria to check the model robustness, overfitting and the potential outliers in the X and Y space were employed. The PLS results indicate that new experimental toxicological data would be needed for five out of the 46 OPs, to improve their known ADI values, for qualitative and quantitative dietary long-term risk assessments.