Early beginnings in Nigeria:
Between 1920 and 1960, through partnerships with mission agencies/ churches existing in Nigeria, TLMI provided financial and technical assistance to leprosy centres in Alushi (Nassarawa state), Numan and Garkida (Adamawa state), Ochadamu (Kogi state), Uzuakoli (Abia state) and Ekpene Obom (Akwa Ibom state) to help restore human dignity and improve quality of life for persons affected by leprosy. TLM continues to be involved in some of the centres above to date.

Invitation from Federal Government of Nigeria:
By the 1940s and 50s Nigeria was ahead of many countries in its leprosy control activities and was involved in pioneering the use of dapsone as a new drug for leprosy care. The program faced a major setback in the 1960s and 70s due to the impact of the Nigerian civil war.

However, in 1988 confronted by the increasing prevalence of tuberculosis and leprosy, the Federal Government of Nigeria (FGN) launched the National Tuberculosis and Leprosy Control Program (NTBLCP) and invited four organizations including TLMI to assist Nigeria in the fight against tuberculosis and leprosy.

So TLMI was subsequently appointed to co-ordinate leprosy control programs in Akwa Ibom and Kwara states. Between 1992 and 1998, TLMI's area of co-ordination extended to include six additional states of Niger, Kebbi, Kogi, Sokoto, Zamfara and Federal Capital Territory (FCT), Abuja. The eight states covered by TLM have a population of over 22,886,510 people and a surface area of 259,952 km². There are about 20, 000 leprosy-affected persons residing in the area, most of whom have been cured but suffer residual deformities, while others still have active disease for which they are receiving anti-leprosy treatment. There are perhaps thousands yet to be diagnosed.