Background: PHBS (clean and healthy living behavior) hand washing is very influential on the incidence of diarrhea in infants (0-1 years), mothers play an important role in it. Objective: The purpose of this study was to determine the effect of PHBS (Clean and Healthy Living Behavior) hand washing via WhatsApp virtual video on the incidence of diarrhea in infant (0-1 years) in Gandoang Village, Bogor Regency in 2021. Methods: This type of research uses Pre-Experimental research in the form of One Group Pretest - Posttest research. The population in this study were mothers who had infant children (0-1 years old) in Gandoang Bogor Village in 2021 and the sample required in this study was 20 respondents using the Total Sampling method. Research data analysis using Mc Nemar test. Results: Based on the results of the research, before being given PHBS education on hand washing on the incidence of diarrhea >3x as many as 12 respondents (60.0%). The picture after being given PHBS education about washing hands on the incidence of diarrhea >3x as many as 3 respondents (15.0%). The result of statistical test is known with P value = 0.004 < 0.05. Conclusion: There is an effect of PHBS (Clean and Healthy Living Behavior) washing hands through virtual WhatsApp videos on the incidence of diarrhea in infants aged (0-1 years) in Gandoang Village, Bogor Regency in 2021.