摘要:The aim of this study was to compare the scores of maternal self-efficacy for child diarrhoea prevention, between intervention and control groups, according to sanitary, social and demographic characteristics. A randomised clinical trial was carried out on 163 mothers of children under 5 years old. Data collection was conducted during two months, at two different moments (M0 and M1); at the moment M0 only the intervention group watched the educational video to promote self-efficacy for child diarrhoea prevention; at M1 (two months later) the scale was applied to both groups. In the intervention group, greater mean self-efficacy scores were obtained compared with the control group. The following variables showed statistically significant associations (p < 0.05) with maternal self-efficacy: age 35 or over; high school education; working outside the home; residence with 4 to 5 people; house not of brick or mortar; public refuse collection; piped water supply; consumption of mineral water; and public sewerage network. After use of the video “Diarrhoea: you can prevent it”, the maternal self-efficacy increased, proving that this strategy is able to assist the nursing staff in educational practices.