Problem: The paper tools used to monitor outreach work in all major cities in Viet Nam had substantial writing requirements for each contact with difficulty maintaining confidentiality. Action: This paper describes the development of a Unique Identifier Code (UIC), a field data collection notebook (databook)and a computer data entry system in Viet Nam. The databook can document 40 individual clients and has space forcommodity distribution, group contacts and needles/syringe collection for each month. Outcome: Field implementation trials of the UIC and databook have been undertaken by more than 160 peer outreachworkers to document their work with people who inject drugs (PWID) and sex workers (SW). Following an expanded trialin Hai Phong province, there have been requests for national circulation of the databook to be used by peer educators documenting outreach to PWID, SW and men who have sex with men. The standardized UIC and databook, in a variety of locally adapted formats, have now been introduced in more than 40 of the 63 provinces in Viet Nam. Discussion: This development in Viet Nam is, to our knowledge, the first example of the combination of a confidential UIC and an innovative, simple pocket-sized paper instrument with associated customized data-entry software for documenting outreach.