The objective of this study was to verify the effects on 4- to 18-month-old babies' NPMD after the family-centered Kids Intervention Therapy -- Aquatic Environment (KITE) programme. This quasi-experimental study involved 61 families. The NPMD was assessed with Alberta Infant Motor Scale (AIMS), Denver II Developmental Screening Test, context assessment with questionnaire and Affordance in the Home Environment for Motor Development -- Infant Scale (AHEMD-IS), and quality of life (QOL) assessment with Pediatric Quality of Life Inventory™ Infant Scales (PedsQL™). 24 babies in the intervention group (IG) participated in the KITE session twice a week for 4 weeks. 37 children participated in the control group. The IG sample had improved NPMD in post-intervention (p = 0.001) and retention (p = 0.002), with a large intervention effect ([eta] = 0.178/0.156). The IG improved in the QOL physical capacity domain (p = 0.023), with a medium effect (d = 0.573). There were no differences between the groups regarding the stimulation received at home, which reinforces the effects of the KITE. It is concluded that the KITE had positive effects on the NPMD and QOL physical capacity domain in the participating.