A diet rich in proinflammatory components and inflammation are suggested to be significant risk factors for multiple sclerosis (MS). This study aimed to investigate the association between the risk of MS and the inflammatory potential of an individual’s diet and dietary diversity through pro-inflammatory/anti-inflammatory food intake score (PAIFIS) and dietary diversity score (DDS). In a hospital-based case–control study, 397 participants, including 197 patients with MS and 200 healthy participants aged over 18 years, were evaluated. The history of smoking, dietary intake, and anthropometric characteristics, including body mass index, waist circumference, total body fat, and fat-free mass were assessed. A validated 160-item semiquantitative food frequency questionnaire was used to calculate the PAIFIS and DDS scores. The mean age of the participants was 32.45 ± 8.66 years, and most were females (274, 79.4%). The PAIFIS score was significantly higher among MS patients than healthy participants (p = 0.001). Between PAIFIS and DDS, only PAFIS was significantly related to MS risk (odds ratio, 1.002; 95% confidence interval, 1.001–1.004; p = 0.001). PAIFIS, as an index of dietary inflammation, can predict MS. Further studies are needed to document these findings.