This study aimed to investigate child and maternal-related predictors of Early Childhood Insomnia (ECI) based on a parent-rated severity in a convenience sample of mother-infant dyads with ECI. We conducted a single-center, cross-sectional prospective study involving infants aged 6-36 months who attended the Pediatric Behavioral Sleep Outpatient Clinic at Marmara University Hospital, Istanbul, over 5 years for ECI. Infant sleep was evaluated by Brief Infant Sleep Questionnaire. Beck Depression and Anxiety Inventories were used to assess maternal depression and anxiety. Predictive factors for parent perceived ECI severity were examined by logistic regression models. Among 759 registered mother-child dyads, the mean age of the children at diagnosis was 15.5 ± 7.5 months, and 56.7 % were male. Overall, 76.5 % of the mothers rated their child's sleep to be a serious problem. The odds of parent-reported serious sleep problems were increased in children who woke up often and spent longer in wakefulness. The strongest predictor of ECI severity was maternal sleep deprivation and having a former colicky infant. In addition, mothers scoring higher on maternal anxiety symptoms were more likely to rate their children's sleep as serious than women with lower anxiety scores. This study further underscored that heightened maternal sleep deprivation, elevated maternal anxiety symptoms, and previous exposure to a colicky infant were significant predictors of the perceived severity of ECI. Future research should explore interventions aimed at improving maternal well-being and infant sleep patterns to potentially mitigate the severity of ECI and its impact on family dynamics.