Background The decision as to whether a patient can tolerate surgery is often subjective and can misjudge a patient's true physiologic state. The concept of frailty is an important assessment tool in the geriatric medical population, but has only recently gained attention in surgical patients. Frailty potentially represents a measureable phenotype, which, if quantified with a standardized protocol, could reliably estimate the risk of adverse surgical outcomes. Study Design Frailty was prospectively evaluated in the clinic setting in patients consenting for major general, oncologic, and urologic procedures. Evaluation included an established assessment tool (Hopkins Frailty Score), self-administered questionnaires, clinical assessment of performance status, and biochemical measures. Primary outcome was 30-day postoperative complications. Results There were189 patients evaluated: 117 from urology, 52 from surgical oncology, and 20 from general surgery clinics. Mean age was 62 years, 59.8% were male, and 71.4% were Caucasian. Patients who scored intermediately frail or frail on the Hopkins Frailty Score were more likely to experience postoperative complications (odds ratio OR 2.07, 95% CI 1.05 to 4.08, p = 0.036). Of all other preoperative assessment tools, only higher hemoglobin (p = 0.033) had a significant association and was protective for 30-day complications. Conclusions The aggregate score of patients as “intermediately frail or frail” on the Hopkins Frailty Score was predictive of a patient experiencing a postoperative complication. This preoperative assessment tool may prove beneficial when weighing the risks and benefits of surgery, allowing objective data to guide surgical decision-making and patient counseling.