Performance in Biology at Kenya Certificate of Secondary Education (KCSE) level is very low nationally and even at Sub County level despite provision of educational resources or inputs by the government. Thus, in the whole country candidates who sat KCSE examinations in the year 2016 only 71,348(13.99%) out of 509,822 scored C+ and above, in 2017, only 11,503(2.1%) candidates out of 546,014 scored C+ and above and in 2018, only 33,126(5.66%) candidates out of 584,924 scored C+ and above. In Ndhiwa Sub County, the performance of Biology was far much below the average for the last four years registering mean scores of: 4.83 in 2015, 2.90 in 2016, 2.27 in 2017 and 2.90 in 2018. The purpose of this study was to establish the influence of students’ factors on performance in Biology in public secondary schools in Ndhiwa Sub-County. The study established that students’ factors in Biology accounted for 11.6% of the variation in performance in biology however, the influence was not significant because the p-value was greater than 0.05. The study recommended that: Schools to intensify use of guidance and counseling to address student factors like punctuality, discipline, consulting teachers, and other factors that lead to poor performance; Quality Assurance and Standards Officer to regularly visit schools and monitor effective learning in schools and encourage provision of more learning resources while parents to devote their time to monitor learners and provide learning resources. The findings of this study will inform policy formulation and decision making with a view to enhancing student performance in Biology.