Home injuries are among the causes of death and disability in toddlers. Preventing home injuries is an essential part of the child health care program. Using education-based models interventions can promote mothers’ practices regarding home injuries. This study aimed to investigate the effect of education based on the theory of planned behavior (TPB) on the mothers’ preventive practices regarding toddler home injuries. A quasi-experimental study was conducted on 116 mothers referred to comprehensive health centers (58 mothers in each experimental and control group), who were selected using the cluster sampling method. Data were collected using a researcher-developed TPB questionnaire, which was validated by I-CVI (≥0.78), and CVR (≥0.79). Its reliability also confirmed by Cronbach’s alpha coefficients (.52-.93). Afterward, educational intervention was implemented in the experimental group based on TPB in four 45 to 60 minute sessions. After 2 months, the data were recollected from the two groups and analyzed using SPSS software version 16. Comparing the scores of TPB constructs (i.e., perceived behavioral control, behavioral intention, and subjective norms), and mothers’ preventive practices regarding toddler home injuries revealed no statistically significant difference between the 2 groups pre-intervention. However, after the intervention, significant differences were observed between the 2 groups in terms of awareness, the TPB constructs (except for subjective norms), and preventive practices of the mothers ( p < .001). Mothers’ preventive practices regarding toddler home injuries were improved after applying TPB; hence, it is suggested a larger study be completed to confirm the results of this theory-based education.