The paper aims to explore the myth of fertility associated with Oldoinyo Lengaiand its impacts to the Maasai community in the Gregorian rift valley system innorthern Tanzania. It assumes that in African spirituality, myths are used toguide knowledge, values and practices in the community and Mother Nature.Fertility is among the major transformation event in human life circles that canbe reflected through community myth. Through in-depth interviews andobservation techniques primary data relating to culture, customs and traditionswere obtained. Documentary search was employed to supplement field data. Thestudy found out that the Maasai community depended on the Oldoinyo Lengai(Mountain of God) for the fertility of human and animals. The fertility mythamong the Maasai pressurized them to prefer many children. The myth alsoencouraged the dominance of promiscuousness; and the deterioration of healthdue to bearing many children with limited maternal health care and the spreadof sexually transmitted diseases. Thus the myth of Oldoinyo Lengai in relation to fertility has caused an incredibly adverse impact on the Maasai community, particularly in Tanzania. The study recommends that health education and services be extended to villages in the vicinity of Oldoinyo Lengai with service providers who are well-trained to integrate the nature of the myth and its side effects to the community in relation to the changing socio-economic landscape. Moreover, it is imperative to empower the community members economically and socially so that they can decide their fate and exercise their consent.