Introduction. Many surgical formulas have been developed and proposed based on the experience of surgeons to improve the predictability of strabismus surgery. However, the consent among strabismus surgeons regarding the dose effect of the extra-ocular muscle recession or resection was not achieved yet and the disagreement about the appropriate amount of strabismus surgery still exists. Our study aimed to elaborate a postoperative angle of deviation (PAD) predictive model using simple potential predictors in concomitant exotropia. Methods. The analytical prospective clinical study was conducted from April 2016 to July 2019, on a sample of 56 patients (aged between 4–58) with concomitant exotropia who underwent strabismus surgery in Clinical Republican Hospital ”Timofei Mosneaga”and Children Hospital “Em Cotaga” from Republic of Moldova. The correlations of patients’ age, strabismus type, amblyopia degree, resection and recession length, preoperative angle of deviation (PreAD) with PAD were estimated using Pearson’s correlation analysis. Results. Exotropia strabismus surgical treatment outcomes were correlated with the pre-operative angle of deviation (p < 0.001), age at surgery (p < 0.011); EOM recession length (mm) (p = 0.015), EOM resection length (p < 0.001), LRM and MRM insertion distance (p=0.01, and p= 0.02. A stepwise multivariate regression model revealed that preoperative angle of deviation EOM recession length and EOM resection length contributes meaningful information in the prediction of postoperative outcome Conclusions. In our study we propose a mathematical model as potential instruments for PAD modelling in concomitant exotropia surgery.