Many community based outreach programs in low income countries utilize illiterate women to provide health services. However, illiteracy may present special problems in immunization or other programs requiring extensive record-keeping and follow-up. In a trial involving twenty-nine volunteers from urban slum communities in Dhaka, Bangladesh, a community-based referral and record-keeping system for use by semi-literate and illiterate volunteers in immunization outreach activities was evaluated over a thirteen month period. The women were uniformly, regardless of literacy, able to use the system to effectively refer and follow-up clients. Although volunteer performance as measured by numbers of referrals was below initial targets, completion rates were high; 87% of children and 96% of women referred completed the full series of immunizations. By facilitating active community participation, the system provides a feasible approach to reducing the high drop-out rates currently associated with immunization programs.