Background: Substance abuse is self-administration of drugs for non-medical reasons, in quantities and frequencies which may impair an individual’s ability to function effectively and which may result in social, physical and emotional problems. Substance abuse is becoming a serious ongoing public health problem; it affects almost every community and family in some way. The common substances abused in most African countries including Ethiopia are alcohol, chat and tobacco Objective:To assess Knewledge, attitude and practice toward substance abuse abuse among the community of kebele 08 community, ShenkorWereda, Harar town, Eastern Ethiopia from December 10, 2020 – February 1, 2021. Methodology: Community based cross-sectional study using a pre-tested structured self-administered questionnaire was conducted from December10, 2020 to February 01, 2021.Simple random sampling technique was used to select 379 respondents from kebele 08, Shenkorworede, Harar town, Eastern Ethiopia residents. The data collection was done using a self-administered structured questionnaire and the data was entered and analyzed by using statistical package for social science version 24. The result is presented in tables and figures. Result: In this study 379 respondents were included. The 206 (54.4%) of the respondents were abused to drinking alcohol, while 61.5%, 32.7% and 13.7% of the respondents were abused to chewing khat, smoking cigarettes and hashish respectively.The 201(53%), 55 (14.5%), 48 (12.7%),30(7.9%),32(8.4%) of participants responded that smoking causes heart attack, diabetic ulcer, impotency, bladder cancer and poor wound healing respectively. The health risks of khat chewing reported by the participants were constipation 58(24.1%), loss of appetite 34(14.1%), gastritis 33(13.7%) and teeth problem 22(9.1%) respectively.In the current study age [AOR=19, 95% CI: 2.46-19.46] and educational status [AOR=43.19, 95%CI: 8.42-187.84] are associated with knowledge about substance abuse. Conclusion and Recommendation: Despite high level of knowledge regarding substance abuse, the prevalence of substance abuse among community remains high.