The study probed the management of non-instructional time by undergraduates in Southern Nigerian Universities. A research question was raised and one hypothesis was proposed for the study. All undergraduates in ten Southern Nigerian Universities during the 1999/2000 session comprised the population of the study. The sample was made up of 535 undergraduates selected by simple random sampling technique based on the criteria of field of study, place of residence, sex and martial status from three conventional universities. An instrument-titled "Management of Off-instructional Time by Nigerian Students' Questionnaire (MOITNUSQ)" was utilized to elicit information form the respondents. The generated data were analyzed by the use of simple percentage, graphs and chi-square statistic. The findings of the study indicate that Nigerian undergraduates manage non-instructional time poorly in favour of social and economic activities and in disfavour of academic work. Furthermore the bulk of time spent on social activities by the students is focused on religious activities. In addition students were homogenous in their management of non-instructional time since there were no variation in the use of time based on the criteria of sex, field of study, place of residence and marital status. In view of the findings of the study, recommendations were made to aid students to manage non-instructional time more efficiently and effectively. (Contains 3 figures and 2 tables.)