It is a plausible proposition, that in some regimes threatened by opposition and with its legitimacy disputed; as well as in most 'revolutionary' regimes, the instruments of criminalization (laws and their enforcement apparati) may be strengthened to allow for the criminalization of past and present political or economic acts of both opponents and dissenters. Many of these could be middle and upper class persons aspiring to political leadership, or those removed from political and economic leadership. Persons from such classes and strata may be overrepresented in the prison population under the conditions enumerated. Therefore, the question of the demographic and socio-economic status distribution among prison inmates should remain open to continuous investigation - more so over time and across political systems. The composition of the prison population may depend on the prevailing or on prior political and economic struggles in the society, as well as on the political and economic cleavages of the society. There is a dearth of information on the socio-economic composition of Nigerian prison populations. This study examines the socio-economic characteristics of inmates of a Nigerian prison. We found that most of the prison inmates are from the lower socio-economic strata: lower occupational and income categories, and have low educational attainments. The first offenders are not significantly different from the recidivists in these socio-economic characteristics; however, first offenders tend to have larger family size that the recidivists, even through there are no statistically significant differences in the age distribution of the two categories of offenders. The explanation of the preponderance of lower socio-economic strata persons in the prisons is to be sought less in the bio-psychological deficiencies, and mis-socialization in sub-cultural environments theses; and more in the complex relationships between and impact of: (i) more intense pressures for deviance due to social, economic, and political deprivations; (ii) the intense enforcement of law against them; and (iii) vulnerability to criminalization through legislative/judicial processes. (Publisher abstract)