Abstract: This research carried out in Kenyatta University and Maseno University. The objective of the research was to establish challenges that students encountered during their transition from high school to university and how they overcame them. Research data were obtained through stratified cluster random sampling with male students (N=773) and female (N=510) participants. The data for this mixed-model research were obtained through self-administered survey questionnaire in face-to-face administration followed by in-depth interviews. The complementary nature mixed-model helped clarify issues that otherwise would have been overlooked in a mono-method. The survey and interviews data were analyzed separately. The results were integrated with quantitative priority in a thematic sequence of student aspirations, motivation to go to the university, students' self-perception, experiences in high school, institutional climate and interpersonal relations in high school, evaluating students' preparations (academic and social) for going to the university, accessing information, admission process and orientation programs, experiences in the university, satisfaction and adjustment during the transition process. The research revealed factors that affect effective transition process. These included: student personal development, institutional issues, political issues, and ethical issues. The factors related to personal development included self-perception, dynamics of student aspirations, and dynamics of student motivations, autonomy and freedom. The institutional issues included the resources, personnel and communication. Pedagogical issues included adaptation to varied teaching styles, inadequate instructional material and quality of personnel. Considering political issues involved a focus on policies that affected the transition process, disparities among high schools, financing education, and interruptions of the university programs. Ethical issues concerned behaviors and interpersonal relations that affected the transition process and teaching and learning environment. From the research, it may be concluded that effective transition from high school to university in Kenya requires students' personal initiative, support from their high school teachers and administration, and cooperation of the university admissions personnel. Providing detailed and updated information concerning the admission criteria, subject cluster combinations criteria for specific programs, and constant communication between the high schools and universities stand to improve the conditions. Upon taking up their admission, hospitable reception, continued effective orientation especially in the first semester through the cooperation of the university administration personnel and the lecturers, and involvement of the senior students stand to facilitate the transition process among the new students. The students recognized great inadequacies in information and preparations in the university.