Background <p>Edentulism negatively affects masticatory function, nutritional status, and oral health-related quality of life (OHRQoL). This study aimed to evaluate the association between prosthetic rehabilitation type, nutritional status, and OHRQoL in completely edentulous patients.</p> Methods <p>A total of 140 completely edentulous patients were included in this cross-sectional study and divided into three groups: conventional complete dentures (CD), implant-supported overdentures (IOD), and implant-supported fixed prostheses (IFP). OHRQoL was assessed using OHIP-14 and OHQoL-UK, while nutritional status was evaluated using the MNA-SF. Statistical analyses were performed to compare groups and assess correlations.</p> Results <p>Patients with implant-supported fixed prostheses demonstrated significantly more favorable OHRQoL and MNA-SF scores compared with conventional denture users (<i>p</i> &lt; 0.05). Significant associations were observed between oral health-related quality of life measures and nutritional status.</p> Conclusions <p>Implant-supported prosthetic rehabilitation was significantly associated with more favorable oral health-related quality of life outcomes, while differences in nutritional status were also observed among prosthetic rehabilitation groups.</p>