The objective of this research is to study the correlation between Big Five Model andrnpurchasing decision of cosmetic products in the case of female consumers in Addis Ababa,rnEthiopia. The Big Five Model is classified according to the personality traits taxonomy:rnopenness (O), conscientiousness (C), extraversion (E), agreeableness (A) and neuroticism (N)rn(OCEAN). A quantitative research design has been selected as the most suitable method torncollect data from the targeted respondents for this study. A response of 380 sets ofrnquestionnaire has been distributed and 319 questions were received from the female cosmeticrnusers in Addis Ababa. Descriptive frequency and percentage have been conducted to explorernthe demographic characteristics of the target respondents. Using Multiple Linear Regressionrnmodel, this research is useful to examine the relationship between the five independentrnvariables (OCEAN) to one dependent variable (purchase decision) after meeting all the givenrnassumptions successfully. Statistical Package for Social Science (SPSS) version 26 was used torngenerate the actual results The results confirmed that personality factors like Openness,rnConsciousness, Extraversion and Agreeableness as having a positive significant relationshiprnwith purchase decision whereas, Neuroticism proven to have a negative and significantrnrelationship with purchase decision. The study is useful for market to determine personalityrntraits of customers in order to segment the market based on different personality traits ofrnfemale consumers