Human-wildlife conflict (HWC) exists in different forms all over the world and is experienced more in developing countries. The conflict between human and wildlife ranks among the main threats to biodiversity conservation and has become frequent and severe in different parts of Africa. In the author s' previous study, five species of wildlife were identified as the main crop raiding species in Gera, southwestern Ethiopia. The current study was conducted to assess causes of HWC and types of damage in this area. Data were collected through semi-structured questionnaires, focus group discussion, direct observation and key informant interview. Descriptive statistics was used to analyze the socioeconomic profile of the respondents. One-way ANOVA and Chi-square test were used to analyze causes of HWC. The result showed that 50 and 22% of the respondent reported that the prevalence of HWC is manifested through crop damage and livestock predation, respectively. There was a significant difference between causes of HWC (F=4.2, P=0.000). In this study, habitat disturbance and increase in population of wildlife was the highest and least causes of HWC, respectively. HWC is increasing in both severity and frequency in the study area. Therefore, to minimize the conflict occurring in the whole scope of society in the proper selection of investment site (mainly modern coffee production in the area) is crucial. Furthermore, the wildlife authorities and local institutions are encouraged to address the needs of the local communities or to find the source of alternative livelihood to the society.