The study identified the different cultural concepts that secondary school students' believe in and determined the belief and idea of students about the cultural concepts. It also investigated students' source of information about the cultural concepts and determined the influence of these cultural believes on students' academic performance in Physics. The study employed the use of descriptive survey research design. The sample consisted of 940 secondary school students who were randomly selected from 25 public and private secondary schools in the southwestern region of Nigeria using stratified and simple random techniques. The instruments used for data collection are questionnaires titled "Cultural Belief and Atmospheric-related Physics Concepts Questionnaire" (CBAPCQ) and "Cultural Belief Misconceptions in Physics Achievement Test" (CBMPAT). Data collected were analyzed using inferential and descriptive statistics. Result revealed that among the different cultural concepts held by students, high percentage of them believe that rain falling and sun shining means lion is giving birth. Also, majority of the students claimed that the different beliefs of students about the cultural concepts were superstition and lies. The study identified students' major source of information about the cultural concepts to be grandparents, parents and story books. Also, it was found that cultural beliefs of students have negative influence on the academic performance of students in Physics. The study concluded that students held different misconceptions about cultural belief and values which they take into classroom. It therefore recommends that science teachers should intensify on the teaching of scientific concepts that give better explanation to most of these concepts.