In the past decade, moderated mediation analysis has been extensively and increasingly employed in social and behavioral sciences. With its widespread use, it is particularly important to ensure the moderated mediation analysis will not bring spurious results. Spurious effects have been studied in both mediation and moderation analysis, but this issue remains unexplored in moderated mediation analysis. To fill this gap, we examined the conditions under which a spurious moderated mediation effect in a dual stage moderated mediation model might occur. Specifically, with a hypothetical example and three theorems, we illustrated how the index of moderated moderated mediation may conclude a moderated mediation effect which does not actually exist. As a remedy to rule out the spurious results, we proposed two methods which are simple and easy to implement. Based on the simulation results, we offer researchers some practical guidelines to apply the methods in empirical research.