Aim: This study aimed to assess the incidence and demographics of fifth metatarsal (5MT) fractures, as well as the association of these factors with nonunion rates. Materials and methods: A total of 1,000 adult patients with confirmed 5MT fractures were recruited retrospectively. Patients were screened for union vs nonunion, where nonunion was defined as failure to heal completely within 180 days of fracture diagnosis. Inclusion criteria were: (1) age of ≥ 18-year-old and (2) confirmation of 5MT fracture by experts based on examination and radiograph. Exclusion criteria were: (1) missing data on final healing status, (2) presence of another traumatic injury to the foot during the healing process of the primary 5MT fracture, (3) lack of radiologic proof of healing or nonhealing, and (4) missing demographic data or relevant clinical or operative notes. Data on demographics, fracture characteristics, and treatment methods (conservative vs operative) were also collected. One-way analysis of variance (ANOVA) and Chi-square analysis was used, and p < 0.05 was considered statistically significant. Results: The overall nonunion rate was 22.4%, with zone 2 demonstrating the highest nonunion rate (28.1%). Weight and body mass index (BMI) were correlated with a higher nonunion rate (p = 0.002 and p = 0.012, respectively). Type of treatment (operative vs conservative) and displacement were not correlated with nonunion; however, stratification by both types of treatment and displacement revealed a difference in nonunion between the three fracture zones. Clinical significance: 5MT fracture nonunion remains a prevalent problem. The association between nonunion and weight, BMI, and fracture characteristics can be used by clinicians in the decision-making process regarding treatment and management of 5MT fractures to reduce the incidence of nonunion, improve patient-reported outcomes, and reduce the healthcare burden.