Background: Traumatic brain injury (TBI) patients are commonly faced with excessive muscle wasting and severe malnutrition, despite adequate calories. Malnutrition in TBI patients is associated with adverse outcomes, but the specific factors contributing to this are unknown. Certain factors are associated with a higher risk of malnutrition. Factors looked at in this study are age, sex, race, body mass index (BMI), preexisting comorbidities, surgical intervention, when feeds were started, and what feeds were given. Methods: Data of the TBI patients were collected prospectively from 2nd June 2019 to 8th November 2019 at the Chris Hani Baragwanath Academic Hospital in Soweto, Gauteng. Results: A total of 32 patients were included in the study; two were left out due to lack of consent. About 96.88% of the patients were male, with most patients falling into the age categories of 18–40 years. A minority of patients were mild TBI, with a GCS of 13–15, 4.17%. Of the patients included, the majority was severe TBI, GCS 3–8, 62.5%. Treatment options for the TBI were split evenly for conservative treatment and surgery. Unfortunately, 25% of the patients were demised during this study. The mechanism of injury varied among patients. Fourteen patients were allegedly assaulted, four were involved in pedestrian vehicle accidents (PVA), and eight patients had unknown mechanisms of injury. The prevalence of malnutrition on day 10 of the mid-upper arm circumference (MUAC) measurement was 31.25%, and on day 21, it was 56.25%. The only two factors we found to have a risk for malnutrition in TBI was a longer length of hospital stay, p-value <0.001, and the later feeds were started on the TBI patients, p-value 0.014. Conclusion: TBI is associated with malnutrition at day 10 postinjury as indicated by a reducing MUAC. Delay to initiation of feeding and shorter hospital stay appear to be independent risk factors for malnutrition post-TBI. Further studies are needed to validate this finding.