Although listening is key to communication, it remains the least studied skill compared to other skills, both at the national and international levels, among learners of English as a foreign language (EFL). There is also often a lack of awareness among scholars and teachers of how listening takes place, how it is best taught, and how it can be studied. To fill this gap, this study investigated the process of listening activated by Thai EFL learners while listening for comprehension. Twenty-four undergraduate participants were asked to complete a 30-minute multiple-choice listening test, with stimulated recalls conducted immediately afterward. Their stimulated recall transcriptions, listening notes and test responses were analyzed to identify which cognitive processes and strategies they used while listening and to investigate the extent that they were successful as listeners. The results showed that although the participants activated cognitive processes for listening at both the lower and higher levels, the majority, both high and low ability listeners, reported relying more on processes at the lower level (word recognition and parsing). Common strategies used by the participants are inferencing, elaboration, and comprehension monitoring. The activation of the cognitive processes and strategies was interactive and interrelated in a very complex way. Based on the findings, implications are discussed for how effective listening skills are best taught in the EFL classroom, what kinds of materials should be used, and how listening skills can best be assessed.