Adjustment to University was defined in terms of academic; the study endeavoured to determine the influence of orientation programme on first-year students' academic adjustment in public universities in Kenya; Mixed methods research approach was used. The study utilized a descriptive survey design. Twostage cluster sampling, simple random sampling, and purposeful sampling techniques were employed to obtain 479 respondents from the target population of 71,285. The study was conducted in nine public universities in Kenya between January and April 2019. Data was collected using three research instruments: a questionnaire, focused group discussions, and in-depth interview schedule. The tools were validated by two experts from Kisii University, while reliability was determined through the test-re-test method in a pilot study for a first-year student questionnaire. Both qualitative and quantitative techniques (Content Analysis, Means and Standard Deviations, Factor Analysis, Analysis of Variance (ANOVA), and Post-hoc t-tests) were utilized to analyze data with the aid of the computer-based Statistical Package for Social Sciences (SPSS) version 22.0. Research hypotheses were tested at α ≤ 0.05 level. Findings indicatethat the duration of the orientation programme, activities and how they are carried out together with the location and size of the universities in terms of the student population and organizational structure do influence the level of adjustment realized by first-year students. Besides, academic adjustment was higher in old universities than in new universities. This will inform the design and implementation of diverse guidelines and programmes suitable to meet first-year students' requirements.Further, results will enlighten first-year students to recognize their situation and be encouraged to seek more timely assistance and services. The study recommends that when developing orientation programmes, universities need to identify specific desired outcomes in all areas of first year students’ academic adjustment and create programmes that align with those unique demands.Universities may consider adopting an extended orientation programme by integrating orientation materials into the curriculum during the first semester.

Keywords : Adjustment, academic, programmes, outcomes, first-year and students.