Background: Prescription opioid abuse is an epidemic in the US. Of the abusers, 75% obtain the opioid from a friend or relative, which may be related to improper opioid storage and disposal practices. Our aim was to determine patients’ practices of opioid use, storage, and disposal. Methods: We surveyed 300 cancer outpatients presenting to our Supportive Care Center who were receiving opioids for at least 1 month and collected information regarding opioid use, storage, and disposal along with patient characteristics and scores on Cut-down, Annoyed, Guilty, Eye-opener (CAGE) questionnaire for alcoholism. Sharing or losing their opioids was defined as an unsafe use. Results: The median age of the patients was 57 years; 53% were female, 72% were white, and 63% were married. Most (89%) had advanced cancer, and lung cancer was the most common (22%). CAGE was positive in 19%, 9% had history of illicit drug use, and 36% lived with adult/young adult children. Of the 300 respondents, 19% stored opioids in the open, 69% kept opioids hidden but unlocked, and 9% locked their opioids. Patients with history of CAGE positivity (P=.007), illicit drug use (.0002), smoking (P=.03), and those living with adult children (P=.004) were more likely to keep their opioids locked. 66% were unaware of proper opioid disposal methods. 46% had unused opioids at home. 53% did not routinely dispose opioids, of whom 44% saved them for future use. 26% indulged in unsafe use by sharing (9%) or losing (17%) their opioids, and 44% informed their family and friends that they were on pain medications. 39% were unaware that their opioid could be fatal when taken by others. Compared with married patients, those who were never married [OR=2.92; 95% CI 1.48-5.77], separated [OR=11.38; 1.52-112.5], or divorced [OR=1.27; 0.55-2.91] had higher odds of unsafe use (P=.006). CAGE positivity (40% vs. 21%, P=.003) and illicit drug use (42% vs. 23%, P=.031) were also significant predictors of unsafe use. Conclusions: An alarming proportion of patients improperly and unsafely use, store, and dispose of opioids. Patient education by physicians/pharmacists and creation of more drug take back programs may reduce availability of prescription opioids for potential abuse. More research is needed in this area.