Pemerintah dan Bank Indonesia membuat peraturan terkait dengan program Anti Pencucian Uang yang memuat prinsip mengenali pengguna jasa/Customer Due Dilligence yang kemudian diperluas oleh Bank Indonesia dengan prinsip mengenali pengguna jasa lebih mendalam/Enhanced Due Dilligence. Pelaksanaan Customer Due Dilligence dan Enhanced Due Dilligence serta pengawasan dari perbankan dan Bank Indonesia perlu untuk diketahui sebagai upaya pencegahan tindak pidana pencucian uang. Metode penelitian yang digunakan adalah dengan pendekatan kualitatif, jenis penelitian yuridis sosiologis, pengambilan data dilakukan dengan teknik wawancara dan dokumentasi. Analisis data dilakukan dengan deskriptif kualitatif. Hasil penelitian ini menunjukkan bahwa implementasi Customer Due Dilligence dilakukan pada saat calon nasabah membuka rekening, adanya transaksi mencurigakan, transaksi tunai lebih dari atau sama dengan Rp 500.000.000,00, dan pihak bank meragukan kebenaran informasi pengguna jasa. Enhanced Due Dilligence dilakukan pada calon nasabah Politically Exposed Person saat membuka rekening. Pengawasan internal bank saat pengguna jasa melakukan hubungan usaha, dual checking dan register tersendiri bagi Politically Exposed Person, pelaporan transaksi mencurigakan dan transaksi tunai, pembagian kewenangan pegawai, adanya pelatihan bagi pegawai terkait tindak pidana pencucian uang, dan terdapat pengkinian data nasabah. Pengawasan Bank Indonesia dengan membuat aturan terkait Tindak Pidana Pencucian Uang dan mengawasi pelaksanaannya. Simpulan dari penelitian adalah Customer Due Dilligence diimplementasikan pada saat melakukan hubungan usaha dengan pengguna jasa. Customer Due Dilligence tidak diimplementasikan pada saat transaksi dengan Walk In Customer dengan nominal lebih dari atau sama dengan Rp 100.000.000,00. Enhanced Due Dilligence diimplementasikan pada saat melakukan hubungan usaha dengan Politically Exposed Person, namun tidak dilakukan Enhanced Due Dilligence untuk keluarga Politically Exposed Person. Pengawasan bank dilakukan pada saat melakukan hubungan usaha dengan mapping wilayah, pembagian kewenangan pada pegawai, pelaporan transaksi mencurigakan dan transaksi tunai. Namun tidak dilakukan pengawasan bagi non nasabah. Pengawasan Bank Indonesia terkait dengan Program Anti Pencucian Uang yaitu membuat aturan terkait Customer Due Dilligence dan Enhanced Due Dilligence dan mengawasi pelaksanaanya.Indonesian government and Bank Indonesia made a regulation of anti money laundry in order to prevent any money laundry done by person using banking facilities. Those regulation accomodate a principle of knowing the customer/Customer Due Dilligece broaden by Bank Indonesia by further knowing the customer/Enhanced Due Dilligence. Implementation of Customer Due Dilligence, Enhanced Due Dilligence, and the supervision of both by the banking and Bank Indonesia are important to be understood as a prevention of money laundry. The aim of this study is describing the implementation of Customer Due Dilligence, Enhanced Due Dilligence, and the internal supervision done by branch office of BRI Semarang Pandanaran and Bank Indonesia supervision of anti money laundry program. Research method used by researcher was qualitative approach on sociological jurisprudence, data compilation was done by interview and documentations review, and the data analized by a qualitative dercriptive analizing. This study shows that Customer Due Dilligence was done when customer decided to open a bank account, a suspicious transaction, more than Rp 500.000.000,00 cash transaction, and an enquiry of customer valid information. Enhanced Due Dilligence was done when Politically exposed prospective customer open a bank account. Internal supervision was done on enterprise relation, Politically Exposed Person registration and dual checking, suspicious transaction report, authority apportionment, and update on customer data. Bank Indonesia supervision was done by establishing regulation related to anti money laundering and supervise the implementation. Conclusion of this research is Customer Due Dilligence implemented on enterprise relation with customer. Customer Due Dilligence was not implemented for Walk In Customer by transaction more than Rp 100.000.000,00. Enhanced Due Dilligence implemented in enterprise relation with Politically Exposed Person, but not implemented on Politically Exposed Person’s family. Bank supervision implemented on enterprise relation by area mapping, authority apportionment, and suspicious transaction report, but there was no implementation on Walk in Customer. Bank Indonesia supervision was done by establishing regulation related to anti money laundering and supervise the implementation.