This study investigated peer pressure influence on premarital sexual behaviour of senior secondary school students in Kaduna State, Nigeria. The population for the study comprised students in public senior secondary schools in the twenty-three Local Government Areas of Kaduna State. Simple random sampling was used to select Kaduna North senatorial zones from the three existing zones in Kaduna State. Nine schools from thirty-two senior secondary schools were randomly selected. The population of senior secondary schools in Kaduna North zone was 5,730 in 2010/2011. 50% (2,865) of the population was used as sample size. A total number of 1,655 males and 1,210 female students were used. In each of the nine (9) schools, 319 copies of questionnaire were administered to the Students using simple random sampling technique. The data collected were statistically analyzed using descriptive statistics of mean, and standard deviation. The hypothesis was tested using one sample Z-test at 0.05 level of significance. It was found that, there is significant influence of peer pressure on premarital sexual behaviour among senior secondary school students in Kaduna State, Nigeria. It was recommended, that Kaduna State Ministry of Education to intensify awareness programme on premarital sexual behaviour through workshops or seminars for the students on how to deal with peer pressure, and other social pressures that may lead to sexual intercourse.