Background: Mothers and fathers may experience negative emotions as a result of an unusual early delivery and giving birth to high-risk newborns who require hospitalization in the neonatal intensive care unit (NICU) adds layers of stress on them. Hence, a variety of psychological and emotional services are required. Aim: The aim of this study was to identify common stressors in both parents of preterm children in the NICU and determine the effect of psychological intervention in the form of acceptance and commitment therapy (ACT) on stress in both parents. Materials and Methodology: A total of 60 parents of preterm children were randomly assigned to Intervention Group A and Control Group B. Group A received five sessions of ACT and routine counseling, while Group B received only routine nursing staff counseling. The Parental Stress Scale: Neonatal Intensive Care Unit (PSS: NICU) was used for pre- and postassessments to measure the parents’ stress levels on the 1st and 5th days, respectively. Results: Mothers’ stress levels in the NICU are significantly higher when they have a higher socioeconomic status, a higher education level, and a length of stay of more than 6 days, but significant stress is not found in fathers. ACT, when used along with routine counseling, is effective in reducing stress in both parents. Conclusion: ACT can be combined with routine counseling to help parents cope with depression, anxiety, and stress associated with preterm birth in the NICUs.