This article identifies classroom management problems, their causes, and possible ways to reduce these problems in primary schools located in Delta State, Nigeria. A total of 600 teachers selected from twelve local government areas participated in this study. Data were collected in a checklist containing 27 items and a two section questionnaire containing 19 items. Three research questions and three hypotheses were formulated and tested using percentage, bar and pie charts, chi-square and analysis of variance at 0.05 level of significance. The study revealed that common classroom management problems were related to students shouting, calling names, sleeping and talking/engaging in discussion during lessons. Identified causes of these problems were seen as originating in: overcrowded classrooms; parent neglect of the health conditions of children; and an unhygienic and below-standard teaching and learning environment. School location does not significantly influence teachers' views on identified causes and possible ways to reduce classroom management problems in primary schools in Delta State, Nigeria. (Contains 6 tables and 2 figures.)