The study investigated the effect of cognitive conflict strategy and gender on scientific reasoning skills in conservation Biology among senior secondary school students in Biu Education Zone, Borno State. The study employed a pre-test post-test non- equivalent control group design. Two intact SSII Biology classes from two public co education senior secondary schools were used. 22 male and 33 female students received treatment for six weeks while the control group consists of 25 male and 27 female students.