Introduction If we desire to better understand the processes involved in second language (L2) learning and to make claims regarding learners' attention to and processing of different types of linguistic input, it is important to examine the cognitive processes of interest to us as directly as possible. One method of data collection which allows researchers to do this is protocol analysis, in which verbal reports are collected from the language learner. While this method has been used for over a century in the field of psychology in order to investigate problem-solving and memory skills, it is only within the past few decades that SLA researchers have begun to use protocols to observe the cognitive processes utilized in language behaviours and tasks. As Schmidt has pointed out, ‘The problem in applied linguistics has not been over reliance on first-person reports and data, but an almost total neglect of them’ (1994c: 22). The goal of this paper is to address this situation by examining the strengths of protocol analysis as a method for looking at a variety of cognitive processes of interest to second language acquisition (SLA) researchers. The methods involved in the collection and analysis of protocols will be addressed, followed by a discussion of various linguistic studies which have utilized protocols and how the information gained from such research can inform SLA theory. Finally, both the limitations and benefits of this method of data collection for language acquisition research will be considered.