This systematic review provides a synthesis of randomized-controlled trials of technology-focused family interventions for children with chronic illnesses and their families, focused on describing the current state of the literature and generating recommendations for future family systems work in the field of eHealth/mHealth. Twenty-three studies met inclusion criteria and were included in the systematic review. No identified studies featured an mHealth delivery modality. Relevant data were extracted and studies were assessed for quality. There was great variability with regard to intervention factors (e.g., format) and family-centered intervention targets. There is some evidence that eHealth interventions may lead to improvements in particular domains of family functioning (e.g., family conflict) for some groups of participants. However, mixed results and selection of numerous different intervention targets by investigators make it challenging to draw summative conclusions about the overall effectiveness of family systems eHealth interventions. Future research should move beyond feasibility/acceptability studies and examine family-centered processes as primary outcomes. Future research should also consider novel intervention formats to determine whether intervention effects are more robust for certain groups (e.g., individuals who prefer electronic intervention delivery to in-person intervention).