Nigeria returned to democratic rule in 1999. This ushered in the fourth republic after a long era of military rule in the country. Democracy was highly celebrated, accepted by all and sundry with the expectation that it will engender socio-economic and human development. The prevalent issue therefore is that the body polity has been overhauled by daunting challenges that endanger human security. Using simple percentage, frequency distribution and Chi-square (X2) analytical test reveal that Nigeria’s democracy is disturbed by corruption, electoral institution deficiency, leadership failure. These democratic weaknesses violate freedom from fear and want evident in the sub-standard living condition of Nigerians. The study concludes that undermined human security is a threat to democratic stability of Nigeria. The study recommends that democratic institutions should focus on improving development of human and material resources for the consolidation of Nigeria democracy .