The study investigated time management and effective teaching in senior public secondary schools in River State. The study adopted a correlational design. This study covered teachers in the public senior secondary schools in Rivers State. The population was 7,123 teachers. The study adopted the stratified random sampling technique to select teachers in each of the 23 Local Government Areas of Rivers State, giving a total of 177 teachers constituting 10% of the total population. About 8 teachers were chosen from each of the 23 LGAs in Rivers State. Out of 177 copies of questionnaires distributed, 150 representing 85% were duly completed and returned. The study used the returned copies for the analysis of the study. A questionnaire instrument used for data collection titled: “Time Management by Staff and Effective Teaching Questionnaire (EMTQ) was used for this study. The instrument was divided into two sections: section A and B. Section A contains demographic data of the respondents while Section B contains item statements in different clusters. Each cluster contained items addressing a research question. The instrument was coded with a modified 4-point Likert Scale of Very High Extent (VHE)= 4 Points, High Extent (HE) = 3 points, Low Extent (LE) = 2 points and Very Low Extent (VLE) = 1 point. The instrument was subjected to face and content validation by presenting the instrument to an expert in Measurement and Evaluation, at the Niger Delta University, Bayelsa State. The reliability of the instrument was ascertained Crombach alpha and obtained .98>.71 which proved that the instrument was reliable. The research questions were answered using mean and standard deviation at mean benchmark of 2.5 while T-test was used to test the null hypotheses at 0.05 levels of significance. The findings of the study showed that there is a significant relationship between time management and teaching effectiveness. It showed that when teachers adopt prompt use of time in their job roles, that would lead to teaching effectiveness. It recommended among others that Management of public secondary schools in Rivers State should ensure that teaching activities are guided by the school timetable and Principals of public secondary schools in Rivers State should ensure effective and timely coverage of the curriculum or syllables.