Parental relationship with children is the most natural, unique and enduring bond in the world gifted by God. As child's first education begins at home, so the quality of parental relationship with children may have an impact on child's life as well as school performance. The objective of this study was to find out the association between parental relationship and school performance of children. This was a cross sectional study where class six to ten children aged between 11-17 years was participants. Seven secondary schools were selected in Rajshahi city of Bangladesh for data collection. The self-administered questionnaire was used to find out the quality of parental relationship by using the Inventory of Parent and Peer Attachment (IPPA) scale. To asses school performance face to face interview was conducted to the corresponding class teachers as well as exam result and attendance were also taken from official records. The study period was one year from January 2019 to December 2019. Out of total 385 children, 53.5% were girls and 46.5% were boys. The mean age of the children was 13.63±1.289 years. Good quality of relationship with mother was 96.1% and poor-quality relationship was 3.9%. As well as good quality of relationship with father was 93.5% and poor-quality relationship was 6.5%. This study founded boys seemed to establish better relationships with mother compared to girls. Findings also revealed a positive significant association between children's relationship with their mothers and school performance. There was no significant relationship present between all socio-demographic characteristics and parental relationship except gender and occupation of father. This study found statistically significant relationship between parental relationship and school performance of children. Therefore, awareness among parents about parental relationship should be considered as a part of betterment of school performance.