This position paper addresses the need for stronger theorizing on temporal matters in health psychology. Too few theories in health psychology address temporal matters in the specified psychological phenomena, their relationships, and the explanation for these relationships. This might lead to underestimating existing relationships between constructs over time or missing out on opportunities for advancing our knowledge with regard to dynamic developments of the phenomena of interest. Examples of existing theories and approaches addressing temporal matters in health psychology are provided. Further, drawing from other disciplines, examples of methodological and conceptual approaches are outlined that offer directions on how to optimize our theories with regard to temporal matters. This might start with including time-related theoretical considerations to the definition of psychological concepts already in cross-sectional research and might reach as far as developing dynamic theories for capturing and changing phenomena of interest in real life. Challenges and opportunities of theorizing about temporal matters in health psychology are addressed.