Developmental psychologists have been interested in the cognitive ability of perspective-taking for a number of years due to the apparent link between perspective-taking deficits and Autistic Spectrum Disorder. Most of the research in this area has employed the concepts and techniques of the approach commonly referred to as “Theory of Mind.” The current paper is concerned with an alternative operant account of perspective-taking based on a modern behavioral approach to human language and cognition called Relational Frame Theory. According to this approach, the relational frames of l-YOU, HERE-THERE, and NOW-THEN are central to the development of complex perspective-taking. The present paper reports 3 studies that investigate the development of perspective- taking in terms of these 3 relational frames. In Study 1, 5 age groups of participants ranging from early childhood to adulthood were exposed to a protocol assessing their abilities to respond to relational perspective-taking tasks. A developmental profile was then constructed from the relative performances of the different age groups on this protocol. The findings from Study 1 overall indicated that accuracy increased as a function of age. Studies 2 and 3 were subsequently conducted as controls. Specifically, Study 2 was employed to determine whether the low rates of accuracy recorded with the youngest group of participants in Study 1 was simply a function of the length of the statements contained within some of the tasks. The results from Study 2 suggested that this was not the case. In Study 3 an automated version of the protocol was employed to determine whether the high rates of accuracy recorded with the adult participants in Study 1 was a function of cueing. The results from this study similarly indicated that this was not the case. Overall, the findings from the 3 studies lend support to the Relational Frame approach to the development of perspective-taking as generalized operant behavior.