In this study, AISI 2205 duplex stainless steel was joined with laser welding. Base material and laser-welded samples were kept in simulated body fluid (SBF) for 1, 3, 7, 14, 21, and 28 days. This research investigated microstructure, hydroxyapatite (HA) structure formed on surfaces, surface topography, and corrosion properties of samples which were kept in SBF. Characterization studies were performed by using microhardness, optical microscope, macroscope, SEM–EDS, XRD, and atomic force microscope. According to results, it was found out that HA accumulation was higher on base material surface when compared to weld seam surface, and also calcium-deficient carbonate HA structure with low crystallinity was observed on all surfaces. Very low corrosion rates due to very low weight losses were detected in all samples kept in SBF. The results showed us that heat input changes had an important effect on surface roughness values (Ra), apatite morphology on weld seam surfaces, and corrosion behaviors. Overall, it is considered that laser-welded duplex stainless steel can be used as an implant material depending on surface characterization and corrosion behaviors.