Every material in crime scene, which is considered as evidence, has to be examined by forensic authorities. This can contribute to solve cases and thus to justice. However, entomological evidence seems to be disregarded by some public prosecutors, crime scene investigators and forensic specialists. Disregard for entomological evidence and even simple, unimportant mistakes made during collection and transfer of specimens, identification of species and estimation of post-mortem interval may interact with each other and prevent one from reaching accurate results. The aim of this study was both to identify these lapses and emphasize appropriate precautions to prevent them. Entomological material collected from seventeen cases and their crime scene reports and photographs were examined. The entomological evidence could be seen easily on all of the cases, but mostly there were not any records of entomological evidence in their crime scene investigation (CSI) protocols. In our cases, the particular problem was measuring ambient temperatures. It can be recommended that judges, public prosecutors and lawyers, the most important forensic authorities, should be informed about disregard for entomological evidence and mistakes concerning their collection and transfer. This is the only way to enable entomological examination results to be accepted as evidence in courts.