Purpose: Clinical factors affecting the recovery period in patients with vascular or idiopathic paralytic strabismus were evaluated.Methods: This study involved a retrospective review of medical records of patients diagnosed with vascular and idiopathic acquired paralytic strabismus. Vascular paralysis was defined in cases of hypertension, diabetes mellitus, or cardiovascular disease. The angle of deviation and limitation of extraocular movement were evaluated at each visit. Recovery was defined as the absence of diplopia and complete resolution of limitation of extraocular movement. Factors affecting recovery success and recovery period were analyzed.Results: We retrospectively reviewed data of 145 patients consisting of 87 with vascular paralytic strabismus (cranial nerve [CN] III: 21, CN IV: 28, CN VI: 38) and 58 with idiopathic paralytic strabismus (CN IV: 20, CN VI: 24, CN III: 14). The recovery rate did not significantly differ between vascular (60.9%) and idiopathic (63.8%) groups (p = 0.15). The recovery period was longer in the vascular group (130.1 ± 145.1 days) than in the idiopathic group (92.6 ± 76.6) (p = 0.02). Age at onset was significantly associated with the recovery period in both vascular and idiopathic groups. In the vascular group, the recovery periods were 107.4 ± 74.8 days in CN III palsy, 97.2 ± 51.9 days in CN IV palsy, and 159.3 ± 194.1 days in CN VI palsy. The recovery period was significantly longer in patients with CN VI palsy (p = 0.03). Hypertension was significantly influencing the recovery period in patients with vascular CN VI palsy (odds ratio = 2.54, p = 0.01).Conclusions: The recovery period was longer in patients with vascular paralytic strabismus than in patients with idiopathic paralytic strabismus. Recovery rates were not significantly different between groups. In patients with vascular CN VI palsy, a history of hypertension was significantly associated with the recovery period.