Penelitian ini bertujuan untuk mengetahui pengaruh audit internal dan efektivitas pengendalian interen terhadap pencegahan kecurangan (fraud). Penelitian ini merupakan penelitian kausal, dimana ada pengaruh audit internal dan efektivitas pengendalian interen terhadap pencegahan kecurangan (fraud). Populasi dalam penelitian ini adalah auditor internal dan pegawai bagian verifikasi. Pengambilan sampel dilakukan dengan cara Purposive Sampling, dengan sampel 40 responden. Jenis data yang digunakan dalam penelitian adalah data primer. Metode pengumpulan data yang dilakukan adalah dengan survey melalui pembagian kuesioner kepada responden. Analisis data penelitian menggunakan analisis regresi berganda dengan menggunakan program SPSS versi 19.00 Hasil penelitian menunjukkan bahwa (1) audit internal berpengaruh signifikan terhadap pencegahan kecurangan (fraud), (2) efektivitas pengendalian interen berpengaruh signifikan terhadap pencegahan kecurangan (fraud), (3) audit internal dan efektivitas pengendalian interen secara simultan berpengaruh signifikan terhadap pencegahan kecurangan (fraud). Kata Kunci : Kecurangan, Audit Internal, Pengendalian Interen This study was aimed at finding out the effect of internal audit and the effectiveness of intern control on fraud prevention. This study was a causal study, in which there were influence of internal audit and effectiveness of internal control on fraud prevention.The population of this study consisted of internal auditors and employees of verification section. The sampling technique used was purposive sampling with the sample size of 40 respondents. The data used were primary data. The method of data collection conducted was survey through distributing the questionnaires to respondents. The method of data analysis used was multiple regression analysis which was processed by using SPSS version 19.0. The result of the study shows that (1) the internal audit has a significant effect on fraud prevention, (2) the effectiveness of internal control has a significant effect on fraud prevention, (3) simultaneously the internal audit and the effectiveness of intern control has a significant effect on fraud prevention. keyword : Fraud, Internal Audit, Intern Control