Cervical epidural steroid injections (ESI) are performed either by interlaminar (IL) or transforaminal (TF) approaches; however, there is controversy over which is better for safety and efficacy. This clinical trial aimed to compare the effectiveness of the parasagittal IL and TF approaches for cervical ESI in patients who were suffering from cervical radicular pain. A prospective randomized assessor-blind study. The study took place at a single pain clinic within a tertiary medical center in Seoul, Republic of Korea. This prospective randomized, assessor-blind trial included 80 patients with cervical radicular pain. We randomly assigned patients to the TF or parasagittal IL approach for cervical ESI. The effectiveness of the 2 groups was compared based on pain intensity using the Numeric Rating Scale (NRS-11) at 1 and 3 months. The Neck Disability Index (NDI), Medication Quantification Scale (MQS), and responders at 1 and 3 months between the 2 groups were compared. The pain intensity of both groups significantly reduced after 1 and 3 months after each procedure (P < 0.001). Two-way repeated measures of analysis of variance showed no significant interaction between group and time for cervical radicular pain (P = 0.266), although NRS-11 pain score was lower in the TF group than the parasagittal IL group after 1 month (P = 0.010). NDI, MQS, and successful responders were not different between the 2 groups at 1 and 3 months after the procedure. We observed 7 cases (18.4%) of vascular visualization in the TF group, although no serious complications were found in either group. This study had no placebo control group and limited follow-up time. Parasagittal IL ESI may be recommended over the TF ESI in reducing cervical radicular pain, considering both clinical effectiveness and safety.