The research on “Managerial Effectiveness of Internal Auditors among Small- Scaled Enterprises” dealt and sought answers for the following problems: level of managerial effectiveness in terms of planning, organizing, leading and controlling, and level of contribution of the factors affecting internal auditor’s performance. Specifically, the study used descriptive method of research with three hundred eighty—two (382) internal auditors who were directly involved or connected with works and functions in the auditing, accounting and finance departments of small—scaled enterprises. Simple random sampling was used to determine the sample respondents. Questionnaire was mainly used as a data gathering instrument. This was used to gather, collect and analyze data and was treated and interpreted using appropriate statistics. These were descriptive statistics for means and t—test for inferential statistics. The research then concluded that the managerial effectiveness among internal auditors in terms of planning, organizing, leading and controlling was Effective (E) and on the level of contribution affecting the performance of internal auditors, it was described as Contributive (C). The result came after the statistical interpretation of the data taken from respondents and on basis of parameters included therein.