The SMARTS2 model has been used to estimate UV erythemal radiation (UVER) integrated on a horizontal plane and on vertical planes oriented north and south. The values obtained using the model were compared with experimental data provided by three radiometers YES-UVB-1located on these planes. To quantify the results, the statistical parameters considered were mean deviation, mean absolute deviation and root mean square deviation (RMSD). The results on a horizontal plane show RMSD values of about 10%, when working with aerosol optical depth at 500 nm, and 16% when working with theÅngström β coefficient. As for the results obtained for the north and south planes, these reach very high errors. The RMSD in these cases is 20.5% for the south plane and 32.5% for the north plane, in the most favorable of cases, when there are optical depth values to quantify the load of aerosols. These results do not improve even considering an annual trend, taking into account the different seasons, nor considering different periods throughout the day. We therefore consider that the SMARTS2 is not suitable for estimating the UVER incident on inclined planes.