The critical energy situation in Nigeria suggests the need to study energy and exergy utilization in households, with the aim of pinpointing areas of waste and suggesting alternative measures for effective and efficient utilization of scarce resources. Household energy and exergy consumption trends are thus simulated in this study by considering 125 homes randomly selected in Ibadan, southwestern Nigeria. The energy flow for the first three months of 2009 was evaluated using both primary and secondary data. The results show that average efficiency of household energy and exergy utilization are 62.5 and 21%, respectively. Furthermore, approximately 32% of total exergy losses are caused by refrigerator-freezers, followed by air conditioners (30.0%), lighting from bulbs (16.2%), ironing (5.0%), and fluorescent light (3.7%). Other appliances accounted for less than 2.0%. This study provides fundamental guidelines and baseline data for policymakers in Nigeria on sustainable energy policy measures that would reduce energy losses at the household level. DOI: 10.1061/(ASCE)EY.1943-7897.0000083. (C) 2012 American Society of Civil Engineers.