Data on 7,632 households from the 1999 Nigeria Demographic and Health Survey are used to examine household structure and living conditions in Nigeria. The study finds significant disadvantage in living conditions of single-adult, female- and single-adult, male-headed households relative to two-parent households. Extended households show no significant advantage in living conditions over two-parent households if headed by women but are consistently advantaged if headed by men. Although extended households do not entirely wipe out the disadvantage of female headship on household living conditions, they show a significant mitigating potential. Efforts to understand and alleviate poverty in Nigeria may need to address simultaneously gender imbalances in access to livelihood opportunities and factors that foster nucleation of family structure into single-adult households.