Composite action is a structural solution that has increasing importance due to the significant potential in performance improvement of structural elements, and simplification of the construction technological process. Although steel-concrete composite structures are now in use for more than a century, certain forms of composite action are still not sufficiently dealt with in modern standards. One of such solutions is a composite truss system, which is the subject of this paper. This type of construction has advantages that can be utilized in medium and large spans, and in comparison to steel trusses has a lower height. When it is combined with trapezoidal sheets for composite slabs it provides a number of practical advantages. Relevant literature reports that with the use of this system load transfer efficiency increases by 20% to 30%, and the shown design example of a building for commercial purposes in composite and non-composite versions supports such a claim.