Population and human development have a close link. Perhaps apart from insecurity, flood, desertification, one of the most discussed issues is population explosion and poor human development in Nigeria. The paper argued that productive population is an added advantage to the growth and development of economies. But Nigeria's population is growing against the Gross Domestic Product (GDP) that does not add value to human development. Nigeria's population is growing with myriad challenges such as high rate of poverty and unemployment and underemployment ratio. That high unemployment in an economy is largely responsible for the insecurity and violent culture in Nigeria. Some causes of population explosion in Nigeria include early marriage, illiteracy, religions, cultural belief system and poverty. The paper proffers that to curb the excess population, Nigeria should discourage excessive procreation, eradicate or at most reduce poverty by empowering youths, women, build and employ youths in industries; provide energy to drive small and medium scale industries to steam up the economy. Children of school age and youths should be made to attend school at least would add value to their development through family planning and sensitization on the need to have the number of children they can cater for. Laws making early marriage a crime should be put in place. The paper uses secondary materials and adopts historical analysis as methodology.