The evaluation of clay wastes (CW) containing boron additives in mortar are reported in this study. CW grounds were added to ordinary Portland Cement (OPC) with different proportions (0%-20%). The effects of CW on the mechanical properties of mortar were analyzed by fresh and hardened concrete tests. The obtained results were compared with those of control samples and Turkish Standards (TS). The results showed that strength values of all specimens containing 1.5% of CW were higher than that of the control sample. With the replacement of 2.5-5.0% of OPC by CW, the strength values were nearly equal to that of control sample. The durability of CW added cement was also examined with the measurements of the weight losses of samples exposed to NaCl solution and MgSO4 solution. The CW affected the durability negatively in a low level. Copyright © Taylor & Francis Group, LLC.