In this investigation, totally 250 cockroaches were collected from five hospitals of Hamedan County. Four cockroach’s specimens were identified including: Periplaneta Americana, Blattella germanica, Blatta orientalis and P. australasiae. The most predominant specie was Blattella germanica (88.8%), and the less was Blatta orientalis (0.8%) (Figure 1). Table 1 shows the number of cockroaches’ species collected from various sites of the Hospitals. The samples were collected from 14 different places. The maximum numbers of cockroaches were collected from cook house (32.4%) and the minimum were collected from surgery ward (1.2%).