Brick masonry in solid clay units and cement-sand mortar is practised in many seismically active regions of Pakistan and also in other South Asian countries like India, Bangladesh, and others. The strength and behavior of brick masonry buildings are predominantly governed by the in-plane response of walls. The mechanical properties of masonry are essential input for the numerical models employed to estimate the in-plane response of brick masonry walls. This paper presents the mechanical properties of masonry constituent materials (brick and mortar) and brick masonry wallets for mechanical characterization. Masonry prisms (9 specimens) in three different mortar mix are tested for compression strength. A new test setup is developed and employed as part of this research study to conduct diagonal tension tests on masonry wallets (12 specimens) in a more stable and convenient position. Empirical relationships are also developed using regression analysis whereby the compressive strength of mortar is related to the compressive strength and diagonal tension strength of brick masonry. The mechanical characterization and the empirical relations will help in future applications in the context of design and assessment studies of brick masonry buildings.