Background In recent years, increasing studies have focused on motor function/dysfunction in PICU survival. However, most studies have focused on adults and older children. This study aims to investigate gross motor developmental function outcomes in infantile and toddler pediatric intensive care unit (PICU) survivors and the factors associated with gross motor developmental functions.Methods Thirty-five eligibles were divided into dysfunctional (n=24) or non-dysfunctional (n=11) group. Baseline gross motor function for all participants before PICU admission was measured via the Age and Stages Questionnaires, Third Edition (ASQ-3). The Peabody Developmental Motor Scales, Second Edition (PDMS-2) was used to evaluate gross motor development function before PICU discharge.Results The gross motor developmental dysfunction incidence was 68.6% in this study. Linear correlation analysis showed that the GMQ was positively correlated with pediatric critical illness score (PCIS, r=0.621, P<0.001), and negatively correlated with length of PICU stay (r=-0.556, P=0.001), days sedated (r=-0.602, P<0.001), days on invasive mechanical ventilation (IMV; r=-0.686, P<0.001), and days on continuous renal replacement therapy (CRRT; r=-0.538, P=0.001). Linear regression analysis showed that IMV days (β=-0.736, P=0.001), sepsis (β=-18.111, P=0.003) and PCIS (β=0.550, P=0.021) were independent risk factors for gross motor developmental dysfunctionConclusions Gross motor developmental dysfunction in infantile and toddler PICU survivors are more common and may be exacerbated by experiences associated with longer IMV days and increasing illness severity combined with sepsis.