The study determined the degree of implementation of the language provisions in the National Policy on Education(NPE)in Nigerian primary and secondary schools. The study adopted the survey design. The sample size consisted of1,620 pupils in primary schools, 1,620 students in secondary schools totalling 3,240 and 300 English Languageteachers. The 3,240 students and pupils were selected using stratified random sampling technique while the 300English Language teachers were selected using convenience sampling techniques from three senatorial districts ineach of the six states (Ekiti, Ogun, Osun, Oyo, On do and Lagos) in Southwestern Nigeria. The language teacherswere made up of 109 males and 191 females. Two instruments titled “Degree of Implementation of LanguageProvisions Questionnaire” (DIPQ) and “Degree of Implementation of Language Provisions ObservationChecklist”(DIPOC)were designed by the researchers for the study. One research question was asked and answeredwhile five research hypotheses were tested at the 0.05 level of significance. Data were analysed using simplepercentages, t-test and ANOVA statistics. The results showed that the degree of implementation of the languageprovisions was low as attested to by 94% of teachers and confirmed by the researchers who found that only 10.3% ofteachers used the medium of instruction stipulated in the NPE. Results further showed no significant differences inthe responses of primary and secondary, male and female, rural and urban, and public and private school teachers onthe degree of implementation of the language provisions in the NPE (t= 0.749, p>0.05, t = 0.424, p >0.05, t=0.902,p>0.05, t=0.741, p>0.05 respectively). Furthermore, there was no significant difference in teachers’ experience andtheir responses on the degree of implementation of language provisions in the NPE (F= 0.031, p>0.05). It wasrecommended that appropriate avenues should be provided for teachers’ awareness of the language provisions asspecified in the NPE and adequate strategies should be put in place for their implementation. Proper monitoringwould be required to ensure compliance.