The study examined the opportunity and necessity influences on small and medium scale entrepreneurial engagements in Onitsha anambra states nigeria.Specifically the study described the socio-economic characteristics of opportunity and necessity entrepreneurs in the study area, analyzed the factors influencing entrepreneurial engagement of opportunity driven and necessity driven entrepreneurship in the study area; ascertained the effect of opportunity driven and necessity driven entrepreneurial engagement on the growth of small and medium scale enterprises in the study area, identified the factors influencing entrepreneurial utilization of opportunity among  entrepreneurs of small and medium scale enterprises in the study area. A multistage random sampling technique was adopted to select 150 household heads which represent the sample size. The data collected were analyzed using both descriptive such as percentage, mean and percentage and inferential statistics such as probit and Ordinary least square regression.Result shows that majority of the respondents (60.0%) were between the age 20 – 37 years, also revealed that majority of the respondents 57.3% were male. Majority of the respondents (42.00%) had a large household size between 4 – 7 persons. However, the result revealed that majority of the respondents 94.67 % of  the  respondent  in  the  study  area were literate. Probit regression estimate of factors influencing entrepreneurial engagement of opportunity driven and necessity driven entrepreneurship showed Pseudo R² of 87.42% and 69.69% for opportunity driven and necessity driven entrepreneurship respectively with statistically significant chi-square at 1% level. In terms of the socioeconomic characteristics, opportunity and necessity business ownership seem to have roughly the same determinants (age and gender). A notable exception is perceived for education, for which the coefficient is negative and significant for necessity driven entrepreneurship (p value 0.01) but not-significant for necessity opportunity driven driven entrepreneurship. Regarding an individual’s personality the coefficient of fear of failure, opportunity recognition, proactivene and autonomy are the factors influencing entrepreneurial engagement of opportunity driven and necessity driven entrepreneurship, while a notable exception is perceived for entrepreneur network, for which the coefficient is negative and significant for opportunity driven entrepreneurship (p value 0.05) but not-significant for necessity opportunity driven. Ordinary least square regression model on the effect of opportunity driven and necessity driven entrepreneurial engagement on the growth of small and medium scale enterprises revealed the theF-ratiowas 6.317. On the specific, the result indicates that there is a positive relationship between growth of small and medium scale enterprises (profit) and opportunity driven entrepreneurial engagement in the area. Furthermore inadequate working Capital” on the was the major factors influencing the entrepreneurial engagement of opportunity and necessity entrepreneurs in small and medium scale enterprises The government should also provide adequate skills acquisition machines and equipment to facilitate the empowerment of our teaming youthful population as well as provide loan/capital to enable them start up businesses having been imparted with entrepreneurial skills.