Systemic glucocorticoid use is associated with an increased risk for peptic ulcer bleeding (PUB); however, little is known about whether glucocorticoid use is associated with PUB outcome. We conducted a population-based cohort study to examine the association between preadmission use of systemic glucocorticoids and 30-day mortality following PUB. We identified all patients (n = 7,486) hospitalized with a first-time diagnosis of PUB in Western Denmark between 1991 and 2004. Data on PUB; systemic glucocorticoid use (n = 574; 7.7%), including cumulative dose; use of other ulcer-related drugs; previous uncomplicated ulcer; comorbidities; and complete follow-up for mortality were obtained from population-based medical databases. We computed 30-day mortality and mortality rate ratios (MRRs) comparing glucocorticoid users and nonusers, controlling for potential confounding factors. Thirty-day mortality was 14.0% among users of systemic glucocorticoids and no other ulcer-related drugs and 8.7% among nonusers of glucocorticoids, corresponding to an adjusted MRR of 1.30 (95% confidence interval [CI], 0.81-2.08). Among users of systemic glucocorticoids in combination with other ulcer-related drugs, 30-day mortality was 18.9%, corresponding to an adjusted MRR of 1.54 (95% CI, 1.20-1.99). Among both short-term and long-term users, high-dose glucocorticoid use was associated with a greater increase in mortality than low-dose use. Former use of systemic glucocorticoids was not associated with increased mortality. Thus, preadmission use of systemic glucocorticoids was associated with increased 30-day mortality following PUB. Increased mortality was most pronounced when glucocorticoids were used in high doses or were combined with other ulcer-related drugs.