© 2015 American College of Physicians. Background: Pharyngitis guidelines focus solely on group A β-hemolytic streptococcal infection. European data suggest that in patients aged 15 to 30 years, Fusobacterium necrophorum causes at least 10% of cases of pharyngitis; however, few U.S. data exist. Objective: To estimate the prevalence of F. necrophorum; Mycoplasma pneumoniae; and group A and C/G β-hemolytic streptococcal pharyngitis and to determine whether F. necrophorum pharyngitis clinically resembles group A β-hemolytic streptococcal pharyngitis. Design: Cross-sectional. Setting: University student health clinic. Patients: 312 students aged 15 to 30 years presenting to a student health clinic with an acute sore throat and 180 asymptomatic students. Measurements: Polymerase chain reaction testing from throat swabs to detect 4 species of bacteria and signs and symptoms used to calculate the Centor score. Results: Fusobacterium necrophorum was detected in 20.5% of patients and 9.4% of asymptomatic students. Group A β-hemolytic streptococcus was detected in 10.3% of patients and 1.1% of asymptomatic students. Group C/G β-hemolytic streptococcus was detected in 9.0% of patients and 3.9% of asymptomatic students. Mycoplasma pneumoniae was detected in 1.9% of patients and 0 asymptomatic students. Infection rates with F. necrophorum, group A streptococcus, and group C/G streptococcus increased with higher Centor scores (P < 0.001). Limitations: The study focused on a limited age group and took place at a single institution. Asymptomatic students-rather than seasonal control participants-and a convenience sample were used. Conclusion: Fusobacterium necrophorum-positive pharyngitis occurs more frequently than group A β-hemolytic streptococcal- positive pharyngitis in a student population, and F. necrophorum- positive pharyngitis clinically resembles streptococcal pharyngitis.