Synthetic based mud (SBM), a non-Newtonian fluid is proven to be the optimum mud for almost all drilling operations, for example in high temperature high pressure (HTHP) well, deepwater, unconventional and long extended reach directional (ERD) well. However, at certain conditions, the good performance of SBM will degrade, particularly due to effect of chemical instability under high temperature. In the light of aforesaid concern, the study on nano particles as a smart-fluid in drilling operations has been gaining attention worldwide. Therefore, this study intends to improve the performance of SBM with silicon dioxide nanopowder (nano-silica) at different concentration. The involving parameters in this study include the manipulation of nano particles concentration per amount of a commercial fluid loss control between 20 to 100 , and performance at different temperature (275°F and 350°F). The enhanced formulation has given significant benefits by reducing the filtration up to 41.67 and act as the rheology modifier high temperature condition. In summary, the optimum amount of nano-silica has been identified at 40 of total fluid loss control weight to avoid further rheological and filtration degradation. Copyright 2015, Society of Petroleum Engineers.