The study has examined the Influence of strategic planning in improving academics in public Diploma Teachers Colleges in Tanzania. The study used mixed research methods, under concurrent triangulation design. The purpose of using this design was to bring together the differing strengths and non-overlapping weaknesses of quantitative methods with those of qualitative methods. The sample sizes of 10 colleges out of 35 public teachers Colleges with 140 respondents out of the entire population were selected for the research. The study sample comprised 30 Department Leaders, 10 College Principals/Vice Principals and 100 tutors. The study used three sampling techniques which were simple random sampling, stratified random sampling, and convenience sampling. Data were collected through interview guide, document analysis guide; observation and questionnaires and Quantitative data were analyzed through descriptive statistics and presented using frequency, distribution tables, and percentages and inferentially using Pearson correlation. The qualitative data was summarized, coded and analyzed by the research questions. Pilot testing of the research instruments were conducted in one of the teachers' college where the targeted respondents were given a questionnaire and interview guide. The findings of the study revealed that, majority of colleges that had put a strategic plan in place and incorporate students' academic issues had made considerable value-added progress on their students' academic performance.