The species diversity and infestation level of cockroaches was studied in four different habitats in Addis Zemen town in 2014. The objectives of the study were to determine the species diversity, to determine the factors that contribute for occurrence of cockroaches, to isolate bacteria that reside on the external body of cockroaches and to assess the knowledge of the community about cockroaches. A cross-sectional survey and an experimental study were carried out. Data were collected through field observation, experiment, questionnaires and interview from December 30 to March 30/ 2006. The housing categories were sampled using proportional allocation. Cockroaches were collected using sticky traps and identified using standard identification keys. External body surface of cockroaches was washed in sterile saline and a sample suspension was cultured on four types of media: MacConkey, Nutrient Agar, Chocolate Agar and Tryptic Agar and incubated overnight at 37 o C. The presences of bacteria on cockroaches were diagnosed using Gram staining method. Data collected were analyzed using analysis of variance (SAS version 12.1) and chi-square. The results indicated that German cockroach was the only species identified in the study area during the study period. Number of cockroaches significantly varied among housing categories (F=13.2244, P<0.0001), housing units (F=9.8672, P<.0001), hygienic levels (F= 35.5103, P<.0001), moisture regimes (F=84.4703, F<.0001), crack levels (F=19.1, P<.0001). Areas with poor hygiene level, more moisture and full of cracks brought more cockroaches. Gram Negative and Gram Positive bacteria were isolated from external body surface of cockroaches trapped from various sites. Majority of the 235 people interviewed, i.e., house wives, civil servants and restaurant workers believed that cockroaches are not a serious problem. In conclusion, German cockroach is the dominant species and it carries pathogenic disease causing organisms. Also factors such as hygiene, moisture management and avoiding cracks help deter cockroach infestation. Therefore, appropriate measure should be taken to reduce the spread of parasitic diseases that can be transmitted by cockroaches. Hotels and residential areas must be kept free of cockroach infestation through proper sanitation, disposal of wastes, destruction of cockroach habitats and using insecticides. Keywords: cockroaches, species diversity, abundance, habitat