Barth syndrome is a genetic disorder that affects approximately 1/500,000 boys each year. While treatment of medical complications associated with Barth is of primary importance, there is a concomitant need to look at behavioral and clinical features of the disorder. The purpose of this study was to examine the prevalence of atypical sensory processing in 21 boys with Barth syndrome and to explore if phenotypic patterns of sensory responsiveness may be useful in early diagnosis. Using a mixed methods approach, we found that sensory issues related to feeding and eating were ubiquitous in our sample, with some behaviors such as strong gag reflex identifiable early in development. Specifically, boys with Barth had a strong preference for salty, cheesy, and spicy foods while having an overall restricted repertoire of foods they would eat (e.g., picky eaters). In boys with Barth as they age, auditory sensitivity and auditory filtering issues also emerged as potential sensory-related behaviors affecting academic performance and participation. Overall, this study suggests that early identification of sensory patterns in Barth may assist in differential diagnosis and create opportunities for early interventions that may minimize the impact of these behaviors on function and participation. © 2012 Wiley Periodicals, Inc.