OBJECTIVE: The objective of this study is to examine the impact of the presence of gingivitis/periodontitis on the occurrence of infectious complications (including septicemia, bacterial infections, and mycoses) in hospitalized leukemic adults in the United States. METHODS: A retrospective analysis of the Nationwide Inpatient Sample (NIS) for the years 2004-2010 was performed. All hospitalized leukemic patients aged 18 to 65 years were selected. The association between occurrence of gingivitis/periodontitis and infectious complications was examined by multivariable logistic regression models. A total of 135,692 hospitalizations were due to leukemias during the study period. Among these, gingivitis/periodontitis was present in 0.6%. Septicemia occurred in 27.8% of those who had gingivitis/periodontitis (compared to 19.6% in those without gingivitis/periodontitis), bacterial infections occurred in 19.5% of those who had gingivitis/periodontitis (compared to 10.1% in those without gingivitis/periodontitis), and mycoses occurred in 20.7% of those who had gingivitis/periodontitis (compared to 10.7% in those without gingivitis/periodontitis). Patients who had gingivitis/periodontitis were associated with significantly higher odds for septicemia (OR = 1.58, 95% CI = 1.14-2.19, p = 0.01), bacterial infections (OR = 2.15, 95% CI = 1.51-3.07, p<0.01), mycoses (OR = 2.16, 95% CI = 1.43-3.28, p<0.01), or any infectious complication (OR = 2.15, 95% CI = 1.63-2.84, p<0.01) when compared to their counterparts following adjustment for multiple patient and hospital-level confounding factors. CONCLUSIONS: Poor oral health (as defined by the presence of gingivitis/periodontitis) is an independent predictor of increased risk of infectious complications in hospitalized leukemic adults in the United States.