During a four-year period, librarians collected student data by card-swiping undergraduate students who attended one of the core English composition class-based one-shot instruction sessions provided at a large state-supported doctoral-granting university. Data for students who attended library instruction was anonymized and compared to the same data points for students who were enrolled in the English class but did not attend library instruction. The authors compared student success indicators for the control and treatment groups (GPA, pass or fail status in course, and retention) and found a positive correlation between attending library instruction and student success.