This study is centered on public sector audit and public financial management in Nigeria. It examines the relationship between public sector audit and financial fraud control in the public sector, it determines the relationship between public sector audit and internal control quality, as well as investigate the extent to which public sector audit influence financial reporting credibility. The researchers administered two hundred (200) questionnaires to respondents, out of which one hundred and sixty-two (162) were retrieved and was used for the analysis. To test the stated hypotheses, the researchers made do with chi-square statistic tool. At the end of the analysis, we find that there is a significant relationship between financial fraud control in the public sector, internal control quality, financial reporting credibility and public sector audit. We therefore recommend that performance of training courses, general and private, for accountants in order to enhance their perception of financial rules and public sector audit.