Diversification of livelihoods is a recurrently applied approach for cushioning economic andrnenvironmental shocks on the path to reducing poverty and improving well-being of the households. Therefore,rnthis study was conducted empirically and theoretically to assess livelihood diversification and food securityrnnexus. The study was carried out in Assosa Wereda, BGRS, Western Ethiopia. The study used qualitative,rnquantitative or mixed methods approach. A total of 320 rural households sample were selected from fourrnKebeles using systematic sampling technique. Both qualitative and quantitative data for the study wererncollected via structured questionnaire, key informant interview, FGD and observation. Descriptive statisticalrntools such as mean, standard deviation, X2 tests, percentage, and others like MNL regression model, SDI, LVI,rnHFBM, NFA, DES, HDDS, HFIAS, HFIAP, CSI, Spearman's rho correlation and scatter plot were used tornanalyze the data. The findings of the study identified level of education, dependency ratio, access to irrigation,rnand household urban linkage were significant predictors of diversification of livelihoods. Whereas, land holdrnsize, livestock holding size in TLU, extension contact, cooperative member and total household income didnâ€™trnhave any association with household diversification of livelihoods. The rest determinates were insignificantrnpredictors of diversification of livelihoods. Furthermore, as SDI result showed no diversification ratherrnâ€˜specializationâ€™ in livelihood. The study area relatively endowed with different resource potentials andrnopportunities. However, these resources were exposed to human-induced vulnerability and the opportunitiesrnwere not yet feasible. Likewise, of rural livelihood assets that have sustainable contribution for food security ofrnthe householdâ€™s: access to skill training, modern education access, and cooperation of households werernsignificant. However, these assets were not a guaranty for sustainable food security of the households.rnMeanwhile, households' annual total income has no association with the households' sustainable rural foodrnsecurity contribution. Whereas, the other variables were insignificant. Meanwhile, an average DES of thernhousehold was 1,592.07 kcasl / person / day and only 13% of households consume more than 2,100kcals /rnperson / day and only 0.9% of households consumed variety of diet. Similarly, as HFIAS revealed only 1.6% ofrnhouseholds would never worried about having not enough food. Hence, as HFIAP showed 67.2% of householdsrnwere food insecure. While, as CSI showed also about 62.2% of households identified as food insecure.rnTherefore, as these entire indicators showed, the households faced inadequate physical availability, economicrnand physical inaccessibility, utility and instability of food. Of the common determinants of livelihoodrndiversification and food security, only education levels and dependency ratios of the households werernstatistically significant. Besides, as Spearman's rho correlation coefficient results show, the associationrnbetween livelihood diversification and food security was weak and positive (0.270). The variation of foodrnsecurity explained by livelihood diversification was only 7.29%. The scatter plot of the correlation coefficientrnwas the offline outlier. P-value was 0.001 which was less than 0.05. Hence, the null hypothesis was rejected.rnUltimately, the study therefore, urges more livelihood diversification opportunities for poverty alleviation andrndevelopment, encouraging voluntary villagization programs and infrastructure development, successful creditrnand saving services would be accessible, promoting household centric modern large-scale irrigation schemesrnand livestock rearing, and promoting community based conservation of natural environment. Finally, the studyrnwas important for socio-economic planning and strategic development of the study area.