Objective: One strategy to address the health issues among college students is through bystander intervention. However, much is still unknown about bystander behavior. The purpose of the current study was to assess the feasibility of daily diary methodology as applied to bystander opportunity. Method: Using a convenience sample, we examined (1) the frequency at which students encounter alcohol use risk and SDV risk bystander opportunities, and (2) the association between participants' daily alcohol use and daily bystander opportunity. Participants were a small group of 32 college students (75% women; 100% heterosexual; 93.7% White; 6.3% multiracial; 3.1% Hispanic) who took up to nine daily diary surveys for a total of 207 days. Results: Over 80% of participants completed the required days. Participants experienced at least one bystander opportunity on 24% of days. Participants were significantly more likely to report an alcohol risk bystander opportunity on days when they drank alcohol, compared to non-drinking days.