Glulam-based post-tensioned moment-resisting portal frames were developed by a producer from British Columbia in collaboration with ASPECT Structural Engineers. These modular frames, manufactured from appearance-grade glulam, can be viable solutions for substitution of steel moment frames in predominantly wood-framed buildings. This paper presents an experimental study on the structural performance of post-tensioned glulam moment-resisting portal frames under in-plane lateral loads. A total of twelve frame specimens in four different configurations were tested under static or reversed cyclic loads. The test results show that the behaviour of post-tensioned moment-resisting portal frames was relatively similar under static and cyclic loading, in which non-linear elastic behaviour was observed due to the post-tensioning. The peak lateral loads applied to the tested post-tensioned frames was in a range of 34.1 kN to 61.7 kN and the lateral stiffness ranged from 0.53 kN/mm to 2.65 kN/mm, respectively. Depending of the frame configuration, typical failure modes identified during the testing consisted of a combination of either (i) compression perpendicular to grain failure at the columns on the side in contact with the beam; or (ii) compression perpendicular to grain failure at the beam on the side in contact with the columns; and (iii) screw failure in the column-to-base joints (if present). The tests give a valuable insight into the seismic performance of post-tensioned glulam moment-resisting portal frames.