A retrospective view of several hundred epilayers provides an insight into the factors relating to molecular‐beam epitaxy (MBE). The major source of particulates was found to be associated with the high electron flux in the deposition region of the MBE system, coming from the electron beam evaporator, and with the unstable excess Si deposits in the growth chamber. Reduction of Si accumulation in the deposition zone by containment of the Si flux significantly reduces particulate densities in epilayers. Voltages applied to a tantalum plate, situated adjacent to the growth flux zone, affected particulate densities in the epilayers confirming that a significant percentage of the particulate contamination is derived from charge effects. Other factors affecting the particulate contamination of the epilayer include the stability of the electron beam evaporator, the substrate rotation mechanism, and the method of evacuation of the load lock when transferring the samples into vacuum. Two types of particulate‐related features have been identified. The first type thought to be due to microscopic particulates is decorated by crystallographic defects, whereas the second type, which is free of these defects, appears to be related to shadowing of growth by larger particulates. A correlation in the densities of both types of particulate defects in epilayers grown under a variety of experimental conditions suggests a common source.