The paper examined disciplinary measures and job performance of library staff in academic libraries in Imo State. It was guided by five objectives of the study. The survey research design was adopted for the study. The population of the study is thirty (34) Heads of Departments in the five academic libraries studied. The instrument for data collection was an online questionnaire rated using the four-point scale. Out of the 34 copies of instrument sent, 28 were returned showing 82% return rate. Data generated from the study were analyzed using mean (x) scores. Findings of the study revealed that; indiscipline practices carried out to high extent in the libraries studied are lateness, absenteeism from work and insubordination, causes of indiscipline in the libraries are poor working condition irregular payment of salaries, incompetent leadership, natural tendency to flout laws, lack of upward communication, wrong placement of staff, laxity on the part of managers to enforce discipline and nepotism/ethnicity, disciplinary measures are carried out to a low extent, discipline has influence on job performance of library staff and factors that militate against the adoption of disciplinary measures in the libraries, the respondents strongly agree to lack of policy, favouritism, corrupt leaders, ignorance of rules and regulations by staff, lack of management backing, inconsistency in carrying out disciplinary measures and interference from unions. Based on the findings of the study, the researchers recommend that: orientation should be given to staff, all stakeholders should be involved in the fight against the causes of indiscipline, every act of indiscipline should be given a matching disciplinary measure, disciplinary measures should be maintained in libraries in order to improve job performance and there should be a policy on discipline of staff which should be adhered to strictly without interference from individuals or unions.
Keywords: Discipline, Measures, Job, Performance, Library, Management, Influence, Indiscipline, Policy, Staff.