This study investigated grief reactions and coping strategies of in-school adolescents faced with parental loss in Ilorin, Nigeria. The study adopted the descriptive design of the survey method. Two hundred in-school adolescents were drawn using simple random sampling and purposive sampling techniques. A questionnaire tagged "Grief Reactions and Coping Strategies Questionnaire (GRCSQ) was used for the research. The instrument possessed a reliability coefficient of 0.82 which was established through the test retest method. Two research questions and two null hypotheses were generated and tested using the measure of central tendency and t-test statistical tool respectively. The result revealed that in-school adolescents faced with parental loss experienced series of grief reactions such as anxiety, nervousness, fear, nightmare and shock. These in-school adolescents faced with parental loss have low coping abilities. It was further revealed that there is no significant difference in the grief reactions to parental loss and coping strategies among in-school adolescents based on gender. The researchers recommended that counsellors should constantly organize grief counselling for in-school adolescents who have lost their parents; grief therapy programme which could help to manage various levels of grief reaction among students should be coordinated by the counsellors and help-giving professionals.