The existence of multi-dimensional measures of internal audit effectiveness, and the findings of most prior studies are not consistent. As a result of this, to add knowledge to the existing literature and to give direction to the institutions, the study focused on the comparison of the practices and effectiveness of internal auditing among public higher education institutions in Ethiopia. With regards to the sampling techniques employed towards achieving the objective of the study, proportional stratified random sampling, purposive sampling and census were used for the selection of sample institutions, the relevant department and the appropriate respondents respectively. Following this, a total of one hundred sixty (160) questionnaires were distributed to the internal auditors of the sampled institutions out of which one hundred twenty-one (121) questionnaires were effective. The internal auditors were picked from eighteen sample universities out of the 30 target universities. The respondents were considered based on their direct attachment to the study area. By using analysis of moment structures (AMOS), the confirmatory factor analysis was used to identify a set of items which are strongly related to the variables. The Chi-Square test was applied to analyze the data. Top management support, organizational independence, adequate and competent internal auditors, internal audit charter, quality of internal audit work, career and advancement, management perception of internal audit function value, information technology, and objectivity of internal auditors were used as the proxy measures of internal auditing practices, whereas auditees’ evaluation, added contribution of internal audit, and auditing quality were used as the proxy measures of internal audit effectiveness. Out of these 12 variables employed in the confirmatory factor analysis, only 9 variables (top management support, organizational independence, adequate and competent internal auditors, internal audit charter, quality of internal audit work, information technology, objectivity of internal auditors, auditees’ evaluation, and auditing quality) were supported for further analysis. The findings of the study signified that, statistically, there was no significant difference in internal auditing practices and effectiveness among the public higher education institutions. The following could be the reasons for this insignificant difference: first, most public higher education institutions in Ethiopia are similar in policies, procedures, organizational contexts, rules and regulations, and organizational structure; and second, all the public higher education institutions share the same internal audit manual. It can be concluded that the use of electronic technology or modern auditing system instead of traditional auditing systems will improve the auditing activities of the institutions.