Public universities in Kenya are, today, turning to the use of e-learning in an attempt to cope with the rapidly increasing demand for university education. This research was conducted between February 2012 and February 2014 to determine the challenges affecting the adoption of e-learning in these institutions of higher learning. Data were collected using questionnaires administered to 420 lecturers and 210 students, and analysed through the use of simple descriptive statistics. Lecturers ranked heavy workloads the most serious challenge affecting the adoption of e-learning, followed by: insufficient Internet connectivity, denial of copyrights for their developed e-learning modules, limited information and communication technology (ICT) skills, lack of incentives, shortage of computers/laptops, inadequate computer laboratories, and insufficient time for online interaction. Students, on the other hand, ranked insufficient Internet connectivity the numberone challenge, followed by: lack of computers/laptops, inadequate computer laboratories, limited ICT skills, and insufficient time for online interaction. The paper concludes that as a result of these challenges, the adoption of e-learning is slow and still at its infancy stage in public universities in Kenya. It recommends that universities should invest heavily in the improvement of e-learning infrastructure, e-learning content development, capacity building, attitude change, and enhancement of e-learning awareness.