The geometry of masonry prisms is governed by Annex D of CSA S304-14—Design of Masonry Structures and ASTM C1314-18—Test Method for the Compressive Strength of Masonry in Canada and the United States, respectively. CSA S304-14 requires prisms to be one-block wide and at least three courses tall if grouted, while ASTM C1314-18 allows prisms that are one-half block wide and two courses tall. The larger prism size as used in Canada is hindering their use on jobsites given their excessive weight and cost and limits the number of laboratories capable of testing these prisms to failure. The scarcity of prisms on Canadian jobsites is problematic as reports of understrength constituent materials or other construction-related problems may arise with no means of otherwise confirming the adequacy of construction. An experimental program consisting of 196 prisms was therefore conducted at the University of Saskatchewan to evaluate the influence of prism width and height, bedding type, construction pattern (i.e., stack pattern or running bond), and presence of grout on the resulting compressive strength. Results indicate that prism strength is insensitive to width and so suggest that one-half block wide prisms would be reasonable for use in Canada. These smaller prisms would encourage their construction on jobsites to better allow for confirmation of as-constructed assemblage strength and member resistance.