We performed a single-centre, retrospective study to assess physiologic changes of infants in the cardiac ICU while being held by their parent. Continuous data streaming of vital signs were collected for infants included in the study from January 2021 to March 2022. Demographic and clinical characteristics were collected from the electronic medical record. The physiologic streaming data were analysed using mixed-effects models to account for repeated measures and quantify the effect of parental holding. Comparison analysis was also performed controlling for intubation, pre-operative versus post-operative status, and whether the holding was skin-to-skin or not. Ninety-five patients with complete physiologic data were included in the study. There were no immediate adverse events associated with holding. Heart rate decreased during the response time compared to its baseline value (p = 0.01), and this decrease was more pronounced for the non-intubated and pre-operative patients. The near-infrared spectroscopy-based venous saturation increased overall (p = 0.02) in patients while being held. We conclude that parental holding of infants in the cardiac ICU can be safely accomplished, and the haemodynamic and oximetric profile during the holding is favourable compared to the infants’ baseline prior to holding.