The characteristics of postgraduate supervisors in library and information science in Nigerian universities and their perceptions of the timely completion of doctoral programmes were investigated, employing a questionnaire as data collection instrument. Thirty-eight supervisors from 11 university-based library schools that had already produced doctoral graduates were used for the study, and 23 respondents completed the questionnaire. The findings reveal that the supervisors are highly qualified and experienced in terms of their academic qualifications, employment status, experience in supervisory work, and their involvement in all types of research activities, including serving as external examiners both within and outside the country, and their involvement in managing journals, peer-review of journal articles, etc. The supervisors identified poor writing skills as the major obstacles to the timely completion of doctoral programmes. A t-test analysis and Spearman rho coefficient were used to determine factors that could possibly affect timely completion of doctoral programmes. The results show that gender and the experience of supervisors in term of the number of past and present supervisees had significant relationships with the timely completion of doctoral programmes.