The review presents an update of the work done in the micro heat pipe research and development, with an aim to give updated detailed knowledge to individuals new to the field, as well as to those already working in this area. Presented here is a summary of the recent advances in these devices occurring since the early 1990s. The following review describes the historical development of these devices, along with a review of the steady state and the transient models, sensitivity analyses, recent experimental investigations and fabrication techniques. The critical heat input, dryout length, fill charge, various heat pipe limitations and design have also been discussed in brief. Finally, future research and areas in which additional information is required are identified and delineated. This article has 204 references.