According to Singapore's Ministry of Health, 1 confirmed, imported case of monkeypox was reported on May 9, 2019. The case, a Nigerian resident, arrived in Singapore from Nigeria on April 28, developed symptoms on April 30, and was admitted directly from his hotel to Tan Tock Seng Hospital on May 7 by ambulance. Twenty-three close contacts identified by detailed contact tracing have been offered smallpox vaccination (which protects against monkeypox) and have been quarantined. All health care workers in contact with the patient have used appropriate personal protection. One close contact has left Singapore, and his home country has been notified. Risk in the community is negligible. Human-to-human transmission is uncommon and limited to close contacts.