Specific phobia (SP) typically onsets in childhood and frequently predicts other mental health disorders later in life. Fortunately, childhood SP can be effectively treated with cognitive behavior therapy (CBT), including the exposure-based one-session treatment (OST) approach. Despite empirical support for CBT and OST, clinicians, for various reasons, frequently fail to implement exposure-based therapy in routine clinical practice, including perceived difficulties in implementing exposure. Virtual reality (VR) exposure therapy may overcome some of these challenges and provides an alternative modality of therapy. This preliminary study examined the efficacy of VR OST for 8 children with a SP of dogs (aged 8–12 years) (M = age 10.25; SD = 2.11) using a multiple-baseline controlled case series. Following a stable baseline period of either 2, 3, or 4 weeks, it was expected that specific phobia severity would significantly decline after VR OST and remain improved over the 3-week maintenance phase. Assessments were conducted posttreatment and at 1-month follow up (study end-point). It was found that phobia symptoms remained relatively stable across the baselines, with significant reductions from pretreatment to posttreatment and to follow-up on clinician severity ratings (pre- to post- g = 1.12; pre- to follow-up g = 2.40), target symptom ratings (g = 1.14; 1.29), and behavioral avoidance (g = -1.27; -1.96). The treatment was also associated with clinically significant outcomes, whereby at one-month follow up, 75% of children were considered “recovered” and 88% completed the BAT (interacted with their feared stimuli). This study provides support for the effectiveness of VR OST.