Published Article / In response to the Human Immunodeficiency Virus (HIV) epidemic in the country, the South African Government started with the provisioning of Antiretroviral Therapy (ART) in the public health sector. Monitoring and evaluating the effectiveness of the ART programme is of the utmost importance. The current patient information system could not supply the required information to manage the rollout of the ART programme. A data warehouse, consisting of several data marts, was developed that integrated several disparate systems related to HIV/AIDS/ART into one system. It was, however, not possible to trace a patient across all the data marts in the data warehouse. No unique identifiers existed for the patient records in the different data marts and they also had different structures. Record linkage in conjunction with a mapping process was used to link all the data marts and in so doing identify the same patient in all the data marts. This resulted in a longitudinal patient record of an ART patient that displayed all the treatments received by the patient in all public health care facilities in the province.