Nurses' knowledge of suicide has been underinvestigated. This article summarizes a survey of oncology nurses' knowledge and misconceptions about suicide. Nurses' knowledge of risk factors, suicide potential, and management of a suicidal patient were examined after nurses read a vignette about a suicidal patient with cancer. Analysis included descriptive statistics and content analysis. Approximately 20% of nurses underestimated the patient's suicide risk. Nurses correctly identified an average of three of eight risk factors, but 61% misidentified worries and fears as suicide risk factors or indicators of suicide risk. More than 60% of nurses correctly identified saying goodbye, giving away a treasured object, being a widower, and wishing to be dead as risk factors. Few knew that race/ethnicity (3.23%), male gender (23.66%), and age (31.18%) were risk factors. Undiagnosed mental disorders also increase suicide risk. Physicians and nurses often fail to ask oncology patients about depression, and depressed patients often report only physical symptoms and minimize their depression or suicidal ideas. Before committing suicide, 8 of 10 suicidal people had asked for better management of their physical symptoms, but their suicide risk was not detected. After recognizing any indicator of suicide risk, a nurse should assess risk factors, detect clues, and estimate individual lethality. Few (15.12%) nurses asked about a suicide plan as a nursing assessment, and 37% of the nurses used consultation. Less than one-third of nurses recommended providing safety, protecting the patient, or taking suicide precautions. Such evidence indicates the need for education to enhance knowledge and skill building to improve the interviewing and care of suicidal patients.