Climate for an organization is somewhat like the personality for a person. One of the most important factors for organizational goal achievement of any type is human resource working in different organizational climate. This research is then aimed at dealing the role of selected institutional climate dimensions in determining academicians’ affective institutional commitment in the case of Debre Berhan and Wollo University during the year of 2016/17. A total of 216 respondents were selected using stratified probability sampling technique from each colleges found in the university.  The researchers used two separate instruments Organizational Climate Questionnaire and Affective Organizational Commitment Questionnaire to measure institutional climate and academicians’ affective institutional commitment respectively. Finally, the responses of the respondents were analyzed using SPSS (version 20.0). The findings of the study revealed that there is significant positive relationship between four dimensions of institutional climate and affective dimension academicians’ institutional commitment, i.e. management and leadership style (β=.235, p<.001), Suitable career ladder (β=.195, p<.05), personnel policies (β=.177, p<.05) and fringe benefit and salary package (β=.154, p<.05). And also it has been proved that institutional climate has a significant role in determining academicians affective organizational commitment (R2=.257) which is significant at p=.001. It was also found that there is no statistically significant difference between the mean score of affective commitment of males and females in the universities. Also there is no statistically significant difference between the mean score of affective commitment of three age groups of academicians in both universities. So, the institution’s leaders should improve the level of employees’ commitment, especially affective commitment dimension, and retain them through facilitating those dimensions of institutional climate along with the rest dimensions in order to properly retain and enhance academicians’ affection towards their institution.