To compare the clinical results (28-day mortality and disability at discharge) in patients with Guillain-Barré Syndrome (GBS) treated with immunoglobulin or plasmapheresis at the Regional Lambayeque in Peru Hospital. Patients and methods: Retrospective Cohort Study. Brighton criteria was used for diagnosing GBS, and modified Rankin scale (MRS) was employed for evaluating functional outcome. We used logistic regression for data analyses.Results: A total of 142 cases of GBS diagnosed from 2011 to 2020 were included. GBS presented in a seasonal pattern; 60% of cases occurred in winter and spring. Motor variants (AMAN and AMSAN) accounted for 60% of cases, whereas only 8.5% of cases were typical GBS (AIDP). About 60% of patients were males, and 56% of cases corresponded to the age range of 20-59 SUMMARY years. Patients aged ≥60 years accounted for only 24% of total cases of GBS, but this group had a lethality of 58.3%. Although 28-day mortality was statistically similar in both treatment groups (plasmapheresis or immunoglobulin), we found a trend toward lower mortality in the plasmapheresis group (OR 0.78; 95% CI 0.62-0.97; p=0.062). We found no differences in terms of disability at discharge in GBS patients treated with plasmapheresis or immunoglobulin. Conclusion: Mortality and functional outcome were statistically similar between patients treated with immunoglobulin or plasmatic exchange. However, there was a trend toward lower mortality in patients treated with plasmapheresis.