This study described the classroom behavior and academic performance of Public Elementary School Pupils in San Guinto Elementary School at Pangantucan district during the school year 2012-2013. One hundred twenty -eight pupils were purposively selected to participate in the study. A researcher-made questionnaire-checklist, observation and interview guide questions were used as tools in gathering the data. In analysing the data, the mean, standard deviation and Pearson Product Moment correlation were employed. The findings revealed that the pupils have an ambivalent classroom behavior towards: their classmates and schoolmates; class work and activities; and their teachers and persons in authority. Their academic performance was fair. There is a relationship between the academic performance of pupils and their behavior towards their classmates and school mates, and towards class work and activities which mostly manifest children behavior which likely to happen not only in school where the study is conducted in the Philippine setting but internationally. No relationship exists between the classroom behavior of the pupils towards the teachers and persons in authority and their academic performance. As it is in one way or another manifested in some scenario by other pupils and or learners relates in the global setting.