In recent years, an increasing number of mental health research focused on perfectionism as a concept that impacts psychosocial and behavioral wellbeing of individuals from different age groups (Morris & Lomax, 2014). In contrast with adaptive perfectionists, individuals with maladaptive perfectionism set unrealistically high standards and show rigidity in behaviors toward achievement (Stoeber & Otto, 2006). Research results support that maladaptive perfectionism is associated with a host of psychological problems throughout the life span such as depression, low self-esteem, eating disorders, interpersonal problems, and personality disorders (Boone, Soenens, Vansteenkiste, & Braet, 2012; Gnilka, Ashby, & Noble, 2013; Kenney-Benson & Pomerantz, 2005; Rice, Ashby, & Gilman, 2011; Stoeber, Feast, & Hayward, 2009). Anxiety is 1 of the most recognized mental health problems associated with perfectionism, which can start in early years due to experiencing criticism and high standards for performance (Damian, Stoeber, Negru, & Băban, 2013). Although there is an increase in the number of research studies focused on maladaptive perfectionism in adults, research regarding the mental health treatment of perfectionism in children is in its infancy (Morris & Lomax, 2014). Ashby, Kottman, and Martin (2004) proposed a play-based intervention grounded in Adlerian principles as a developmentally responsive approach that focused on helping children modify maladaptive thoughts and behavior. This single-case design study aimed to investigate the effect of Adlerian play therapy (AdPT) on children’s maladaptive perfectionism and anxiety. Results showed AdPT as a promising intervention that needs to be further studied for its effectiveness in treating children’s maladaptive perfectionism and related anxiety issues.