Methods: In this single-center double-blind randomized controlled pilot study, 46 patients were recruited and randomized by the lottery method. The Visual Analog Scale (VAS) for leg pain, modified Oswestry Disability Index (mODI), and Short-Form 12 (SF-12) were assessed at 1 week, 3 weeks, 6 weeks, 6 months, and 1 year. Results: Both groups were comparable in terms of demographics, preprocedure VAS scores, mODI, and SF-12 scores (p=0.52). At the 1-week follow-up, the steroid group had significantly better improvement than the PRP group (p=0.0001). At the 3-week follow-up, both groups showed comparable outcomes; however, the PRP group had better symptom improvement. At 6 weeks and 6 months, the PRP group had better outcomes (VAS, p<0.0001; ODI, p=0.02; SF-12, p=0.002). Moreover, 17 and 16 patients in the steroid and PRP groups underwent repeat LTI with steroids or surgery because of pain recurrence during follow-up. At 1 year, no difference in outcomes was observed. Conclusions PRP may be a useful alternative to steroids for LTI in lumbar radiculopathy. Although improvement was delayed and 1-year outcomes were comparable, the 6-week and 6-month outcomes were better with PRP than with LTI. Multiple PRP injections may be beneficial because of its autologous nature. However, further studies with a larger number of participants, longer follow-up, and repeat LTIs are warranted to draw definite conclusions.