Objective: Constantly increasing health expenditures lead to the use of generic molecules and generic versions of bortezomib have been used for a long time. The aim of this study is to retrospectively examine the effectiveness, side effects, and reliability of generic bortezomib in newly diagnosed multiple myeloma (MM) patients. Materials and Methods: The data of 95 patients who received four cycles of bortezomib as first- or second-line therapy in a single center were retrospectively recorded. Treatment responses, side effects, and progression-free survival (PFS) rates were calculated and compared. Results: Of the 95 patients, 42 used the original and 53 used the generic molecule. Epidemiological data, MM types, genetic risk groups, laboratory values at diagnosis, and bortezomib treatment lines (as a first line or second) were evaluated and there was no statistical difference between the two groups. When the response rates were evaluated according to International Myeloma Working Group criteria, there was no significant difference (p=0.42). Rates of partial response and higher responses were similar (81% vs. 79.2%, p=0.84). PFS rates were 42.8 months with the original and 37.8 months with the generic molecule (p=0.68). Side effects were seen in 44.2% of all patients, and the most common side effects were neuropathy, cytopenia, and infection. These rates were similar in the two groups (p=0.55). Conclusion: Although this retrospective study is limited in scope, it is the first study comparing the original molecule of bortezomib with a generic version. There were no statistical differences between the two groups in terms of treatment responses, PFS, or side effects. However, large-scale evaluations will help obtain more data on this subjec