Introduction:
The aim of the study is to examine demographic data of people living with human immu-nodeficiency virus (PLHIV) who are lost to follow-up (LTFU) during HIV treatment and care, in order to develop rapid and effective interventions to improve access to services in Yemen.

Material and methods:
This is a retrospective descriptive study of health service data implemented in all sites that provided HIV treatment and care services from 2007-2012. The study population was 1,586 PLHIV registered at pre-antiretroviral (pre-ART) clinics and 995 under antiretroviral (ART) clinics with exclusion of transfers and deaths.

Results:
Most of the LTFU at pre-ART and ART clinics occurred during the conflict period (2011-2012) and among males at age 25-49 years, especially from governorates where the services existed. The first 3 years showed higher rates of LTFU; 90% and 81% were among Yemenis, and 68% and 65% among young males at pre-ART and ART respectively. Sana’a governorate had the highest rate of LTFU among females at pre-ART, while Aden experienced the highest rate of LTFU among females under ART.

Conclusions:
The conflict in Yemen was associated with an increase in the rate of LTFU among Yemeni young males, especially at governorates that experienced political conflicts. In-depth study on LTFU are needed, and improved counselling methods and patient’s tracking systems are recommended.