Background: Inadequate antibiotic therapy and failure to administer antibiotics in a timely fashion have been associated with substantial mortality rates in patients in the intensive care unit (ICU). We analyzed the infection pattern in solid organ transplant recipients as well as the impact of antibiotic resistance and inadequate antibiotic treatment on mortality rates and morbidity outcomes. Methods: Charts of adult solid organ transplant recipients in 2006 from a single institution were reviewed. Data on patients with bacterial and fungal infections acquired within one year after transplantation were compared with the primary outcome of death within 28 days. Statistical analysis included nonparametric tests (Wilcoxon rank sum, Fisher exact, and chi-square) and multivariable logistic regression with p < 0.05 considered significant. Results: Of the 366 patients, 114 (31%) had a total of 208 bacterial or fungal infections, and 44 of them (39%) were admitted to the ICU. Our primary endpoint, the 28-day mortality rate, was 8% overall, whereas the six-month mortality rate was 11%. Patients treated inadequately with antibiotics had a significantly higher mortality rate. The leading causes of infection were multiple organisms, coagulase-negative Staphylococcus, and E. coli, of which 76% were resistant to antibiotics. Antibiotic-resistant infections were associated with longer hospital stays (p = 0.04), intravenous antibiotic use prior to infection (p = 0.04), nucleotide synthesis inhibitor use (p = 0.02), ICU admission (p < 0.01), and respiratory failure (p = 0.03). Most infections were treated inadequately initially (69%) but treated adequately at 24 h (56%). Inadequate antibiotic treatment was significantly associated with younger age (p = 0.04), prior intravenous antibiotic use (p = 0.04), longer stay prior to infection (p = 0.05), and cardiovascular shock (p = 0.014). Inadequate antibiotic therapy at 24 h was associated with a higher mortality rate (14% vs. 2%; p = 0.03) and a trend toward longer ICU and in-hospital stays. Conclusions: Most bacterial and fungal infections were resistant to antibiotics and were treated inadequately initially. Prior intravenous antibiotic use and longer stay prior to infection were associated with antibiotic resistance and inadequate antibiotic therapy. Failure to provide adequate antibiotic treatment within 24 h had a significant impact on the 28-day mortality rate and was associated with other detrimental clinical outcomes.