This study sought to examine the methodological quality and summarize the evidence from clinical trials that examined the effectiveness of physical therapist interventions in the management of nonsynostotic positional head deformities in infants. The following electronic databases were searched: PubMed/MEDLINE, ScienceDirect, CINAHL, Scopus, PEDro, and Web of Science. Two different authors conducted the searches and completed the data extraction. Randomized and non-randomized clinical trials were included. The risk of bias was assessed using the Downs and Black Scale and the Cochrane Collaboration's tool. Six articles were finally included. The main features of interventions included education to parents about positioning, manual therapy, and motor stimulation. The small sample sizes were not adequately powered and methodological quality showed a high risk of bias, mainly from a lack of blinding and limited external validity. There are indicators that suggest that physical therapist interventions may be useful for infants with nonsynostotic head deformities at improving cranial asymmetries and motor development. However, the validity of such conclusion is limited because most trials included had a high risk of bias. More rigorous research on physical therapy, including randomized controlled trials with larger sample sizes, is required in this area. The high prevalence and incidence of nonsynostotic positional head deformities in infants calls for the development of effective interventions. Physical therapists have a promising role in the improvement of cranial asymmetry and motor development. The most reported interventions involved educating parents about positioning and manual therapy. Some studies show that changes obtained after physical therapist intervention were comparable with those obtained after helmet therapy. Early referral to physical therapy may help to prevent or reduce the severity of nonsynostotic positional head deformities. Education about positioning is important to prevent and improve the asymmetry of the baby's head when there is nonsynostotic positional head deformity. Physical therapist interventions can improve motor development in infants with nonsynostotic positional head deformity who have motor delays.