Scaling up of Antiretroviral (ARV) drugs is crucial and should be a perpetual venture in developing countries in-order to increase the survival period of HIV/AIDS individuals. In Tanzania, information on the rate of patients considered as lost to follow up during treatment with ARVs is scarce. The objective of this study was to determine the rate of lost to follow up and treatment outcome among patients attending two care and treatment clinics (CTCs) in Tanga City in north-eastern Tanzania. A descriptive observational study was carried out on cohorts from Tanga AIDS Working Group and Bombo Regional Hospital. The total number of patients identified as "lost to follow up" were 89 of which 14 (15.7%) died. Among those who died, 3 (21.4%) died between the second week and 3 months after ARV initiation. Of those still alive (84.3%; 75/89), 25% (19/75) were still on ARVs, whereas 47 (62.7%) self transferred to other CTCs. Proper patient documentation with actual residence address is a crucial aspect for adherence. Similarly, frequent prompt tracing of patient should be part of any drug interventional programme linking facility and communities.