Problem: Self Help Group (SHG) is a small voluntary association established by 15-20 disadvantaged women from the same socioeconomic background to solve their common socioeconomic problems. Like other groups, the formation, development, operations, structures, and processes of SHGs are the function of group dynamics. Group Dynamics Effectiveness (GDE) of self-help groups is relatively well explored in Asian countries, mainly in India. In Ethiopia, studies on self-help groups are mainly on the challenges of self-help groups and their role in women's empowerment. Hence, there is no available research and literature in the Ethiopian context that informs self-help group dynamics. To that effect, this study aimed to address the critical research gap in understanding self-help group dynamics; whether there is a relationship between members’ socio-economic, extension contact, social participation, and attitude with group dynamics and the extent to which these variables predict self-help group dynamics in the Ethiopian context. Methods: a correlational design was applied. A total of 372 SHG members were selected through simple random sampling. Correlation coefficient and multiple regression were the main data analysis methods. Normality, outliers, and multicollinearity assumptions were assessed and met. Findings: The four predictors (attitude, social participation, socioeconomic profile, and extension contact) significantly predicted and explained 59.3% of the variance in self-help group dynamics effectiveness. Attitude was the strongest predictor (β = .512, p < .001) & uniquely explained 18.5% of the variance in group dynamics effectiveness, while socioeconomic profile of self-help group members was the least predictor (β = .106, P < .005) with 0.5% of unique contribution in the explanation of group dynamics effectiveness. Conclusion: The majority of respondents perceived the group dynamics of their self-help group as moderately to highly effective. This suggests that the SHGs were generally functioning well, but there could be room for improvement in group dynamics effectiveness. A proactive attitude towards the self-help group and its members on the one hand and the degree and frequency of exposure of SHG members to extension contacts have significantly contributed to the effectiveness of self-help group dynamics. The study's findings indicate that the function and potential universalities of self-help group dynamics may extend beyond regional borders, with similarities found in studies in Asia, specifically Indian studies.