Studies assessing the association between admission time to paediatric intensive care unit (PICU) and mortality are sparse with conflicting results. We aimed to evaluate the impact of time of admission on PICU mortality within 48 h after admission. This was a single-centre prospective cohort. We collected data from all consecutive children aged 1 month to 16 years over 10 years. We included a total of 1368 admissions, with a PICU mortality of 6.6%. Compared with daytime admissions, the overall mortality rate (5.3% vs. 8.5%, P = 0.026) and the mortality within 48 h after admission were higher for those admitted during night-time (2% vs. 4.2%, P = 0.021). There were no differences between mortality rates and the day of admission (weekend admissions vs. weekday admissions). The adjusted odds of death within 48 h after admission was 2.5 (95% confidence interval = 1.22-5.24, P = 0.012) for patients admitted at night-time. A secondary analysis assessing trends in mortality rates during admission showed that the last 5 years of study were more responsible for the chances of death within 48 h (odds ratio = 7.6, 95% confidence interval = 1.91-30.17, P = 0.0039). Admission to the PICU during night shifts was strongly associated with death compared to daytime admissions. A time analysis of the moment of admission is necessary as a metric of quality of care to identify the interruption or improvement in the continuity of care. Further studies are needed to assess the modified contributing factors.