A newly developed strain rate dependent anisotropic continuum model is proposed for impact and blast applications in masonry. The model presented adopts the conventional approach of considering different yield criteria in tension and compression. The analysis of unreinforced block work masonry walls subjected to impact was performed to evaluate model performance. Comparison of the numerical predictions and test data revealed good agreement. Next, a parametric study was conducted to evaluate the influence of the tensile strengths in the three orthogonal directions and of the wall thickness on the global behavior of masonry walls.