3D-QSAR studies of persistent organic pollutants (POPs) screening for atmosphere persistence were performed by comparative molecular field analysis (CoMFA) and comparative molecular similarity index analysis (CoMSIA) methods. The mean and maximum half-life estimations for degradation in air of 49 UNEP POPs and possible POPs were modeled. Both groups data have been modeled to obtain an average estimate and a predictive value for ranking and screening purposes. CoMFA and CoMSIA models have given cross-validation regression coefficient (q2) values of more than 0.69 and correlation coefficient (r2) value of more than 0.84, which validated for their prediction, could be applied to predict unavailable data.