Objective: In clinical studies, intravenous theophylline has been reported to be effective in the treatment of postdural puncture headache (PDPH), but its efficacy is not clear to some clinicians due to the small number of patients in these studies. This treatment can be used as an intermediate step in the treatment of PDPH, if the efficacy and safety of theophylline is proven. We aimed to evaluate the efficacy and safety of an intravenous (IV) injection of theophylline on PDPH. Methods: Sixty-five PDPH patients who were injected with IV theophylline according to our "Postdural Puncture Headache Algorithm" were evaluated retrospectively. The primary and secondary endpoints were the degree of headache and the patient's overall response to the treatment, respectively. Treatment safety was evaluated based on the occurrence of adverse reactions. Results: Before the initial theophylline administration, the visual analog scale (VAS) score was 6.0±1.6 points. The VAS scores at one hour post-treatment were 1.8±1.4 points. The mean VAS scores of the patients after theophylline infusion decreased significantly compared to before (p=0.001). Hemodynamic changes due to theophylline were not statistically significant (p>0.05). There were no reports of theophylline-related adverse events in the patient records. Conclusion: An iv injection of theophylline is an effective and safe treatment for PDPH. Intravenous theophylline treatment may find a place between the conservative treatment and invasive interventional therapy in step therapy of PDPH.