IntroductionThe aim was to examine the health status and infectious diseases in a cohort of unaccompanied immigrant minors (UIMs) from Africa in Spain, and to detect if there are differences according to the geographical area of origin. MethodsCross-sectional study in 622 African male UIMs at the time of admission to residential care in Aragon (Spain) during 2005-2019. A physical, nutritional and laboratory examination was performed following sanitary guidelines. ResultsThe mean age of the African UIMs was 16.1 years (SD 1.7; range 13-17). 88.9% were from Maghreb (mean age 15.9 years; SD 1.5) and 14.1% from Western Sub-Saharan (mean age 16.8 years; SD 1). We found that the prevalence of caries, iron deficiency and dermatological problems was significantly higher (p<.05) among Maghrebian, and the prevalence of past and present hepatitis B virus (HBV) infection, intestinal parasitosis, eosinophilia (p<.00001) and latent tuberculosis (p=.0034) was significantly higher in those of Sub-Saharan origin. ConclusionThe most relevant finding was the high prevalence of present HBV infection (14.8%) among Sub-Saharan adolescents. This finding highlights the importance of recommending targeted screening, preventive vaccination programs, and integration into local health care systems that allow for long-term treatment and follow-up as a way to prevent the transmission of HBV infection.