Background Carboxytherapy is a minimally invasive, relatively safe modality that has been used for the treatment of dark circles; however, different flow rates and different injection techniques have been described in the literature. Aim To study the effect of the flow rate on the therapeutic outcome of carboxytherapy in infraorbital dark circles. Methods Eighty patients with infraorbital dark circles were divided into two equal groups: Group A received carboxytherapy at a flow rate of 30 ml/min, and group B received carboxytherapy at a flow rate of 60 ml/min. Patients received weekly sessions for 6 weeks, and the treatment response was evaluated 6 weeks after the last treatment session. Results Significant improvement of the dark circles was detected in both treatment groups. However, no significant difference in the treatment response was found when both flow rates were compared. The frequency of development of side effects was significantly higher in the group receiving CO2 at a flow rate of 60 ml/min. No significant difference in the overall post‐treatment patient satisfaction between the two groups was detected. Conclusion Carboxytherapy is an effective therapeutic modality for infraorbital dark circles. Lower flow rates achieve therapeutic responses similar to higher flow rates but with fewer side effects.