Anxiety disorders are the most common psychiatric disorder in children and have been shown to predict adverse future functioning. Furthermore, 25% of children diagnosed with one anxiety disorder have comorbid internalizing psychopathology and many have coexisting disruptive behavior disorders. Parent training programs, including adaptations of Parent-Child Interaction Therapy (PCIT), have shown promise in treating both internalizing and externalizing disorders in early childhood. Recently, modular approaches to treatment have yielded steeper trajectories of improvement in treating childhood anxiety disorders than standard Cognitive-Behavioral Therapy (CBT) for youth with anxiety, depression, and conduct problems. This study implemented a modular PCIT adaptation, called Brave START (Skills Training & Anxiety Reduction Treatment), developed by the author of this investigation. Participants included seven children aged 3-7 presenting with at least one anxiety diagnosis and clinically significant disruptive behavior. Parents of participants were trained to apply adapted PCIT skills, called the "BRAVE MIND" skills, while leading exposures for their children. The "BRAVE" skills, taught to parents during the first phase of treatment, aimed primarily to reinforce children's approach behaviors and include the use of Behavior descriptions, Reflections, Affection, Validation, and Effective praise. The "MIND" skills, taught during the exposure phase of treatment, aimed to facilitate and motivate the children to engage in exposures. These skills include Modeling, Incentivizing, Negotiating, and Deliberate ignoring. In a third treatment phase that targets disruptive behaviors, parents were taught how to effectively set limits, give commands, and provide consequences for noncompliance. The Anxiety Disorders Interview Schedule--Fifth Edition (ADIS-5) was administered pre-and post-treatment. All participants in Condition 2 (CDI-EXP- PDI) no longer met criteria for anxiety disorders at follow-up. Three of four participants in Conditions 1 and 3 (CDI-PDI- EXP) continued to have an anxiety disorder post-treatment. Six of seven participants completed more Behavioral Approach Test (BAT) tasks at follow-up as compared to pre-treatment. Six of seven participants showed a reduction of parent-rated anxiety scores at follow-up as compared to baseline according to the Preschool Anxiety Scale and Spence Child Anxiety Scale. The Eyeberg Child Behavior Inventory (ECBI) demonstrated that parent-reported disruptive behaviors declined for all participants between base-line and follow-up. All participants were no longer rated by their parents as having clinically significant disruptive behavior at follow-up. Regarding parent behavior change, visual inspection of the mothers' data showed that their positive parenting skills generally increased throughout treatment and their negative parenting skills generally decreased throughout treatment, as hypothesized. Given the increase of effective parenting skills, the decrease in ineffective parenting skills, and the reduction in anxiety, oppositional behaviors, and DSM-diagnoses following treatment, evidence suggests that this intervention is efficacious in treating comorbid anxiety disorders and disruptive behavior during early childhood.