This article introduces the situational theory of problem solving (theory of problem solving) as an extended and generalized version of the situational theory of publics (theory of publics). The theory of problem solving introduces a new concept, communicative action in problem solving, as its dependent variable. To explain communicative action, the theory of problem solving refines the independent variables of the theory of publics: problem recognition, constraint recognition, involvement recognition, and referent criterion. Finally, it introduces a new variable: situational motivation in problem solving. The new motivational variable mediates the effects of antecedent perceptual variables on communicative behavior. We report the supporting evidence for theoretical propositions of the new theory based on structural equation modeling (SEM) testing using survey data.