This report investigates presymptomatic transmission of SARS-CoV-2 in Singapore from January 23 to March 16, 2020. It reviews clinical and epidemiological data for all 243 confirmed COVID-19 cases to determine if presymptomatic transmission occurred. Seven clusters of cases were identified, with 10 cases (6.4% of locally acquired cases) attributed to presymptomatic transmission. Presymptomatic transmission was observed 1-3 days before symptom onset in four clusters. The findings highlight the importance of including a period before symptom onset in contact tracing protocols and emphasize the critical role of social distancing in controlling the pandemic. The study also suggests that asymptomatic individuals may play a role in transmission, underscoring the need for broader infection control measures.This report investigates presymptomatic transmission of SARS-CoV-2 in Singapore from January 23 to March 16, 2020. It reviews clinical and epidemiological data for all 243 confirmed COVID-19 cases to determine if presymptomatic transmission occurred. Seven clusters of cases were identified, with 10 cases (6.4% of locally acquired cases) attributed to presymptomatic transmission. Presymptomatic transmission was observed 1-3 days before symptom onset in four clusters. The findings highlight the importance of including a period before symptom onset in contact tracing protocols and emphasize the critical role of social distancing in controlling the pandemic. The study also suggests that asymptomatic individuals may play a role in transmission, underscoring the need for broader infection control measures.