  This article presents a review of all high-resolution ground-based
mid-infrared observations of high mass protostellar objects (HMPOs) to date. An
introduction to the characteristics of HMPOs and their relationship to the hot
molecular core phase of massive star formation is outlined. I explain why
observations in the mid-infrared of these types of sources are important, and
in particular why high-resolution observations are needed. A summary is given
of the earliest mid-infrared detections of HMPOs, followed by a detailed
account of the most recent observations.
