A subgroup of patients with low back pain (LBP) suffers from low back-related leg pain (LBLP), which can be classified as radicular pain, or somatic referred pain without nerve root involvement. LBLP is considered an obstacle to recovery and a strong negative prognostic factor for medium- and long-term disability. In this review, we aimed to investigate the effectiveness and optimal dose of resistance training (RT) in patients with subacute or persistent LBLP to provide clinical recommendations for practice. This systematic review was conducted by adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the recommendations of the Cochrane Collaboration. We conducted a literature search on PubMed, PEDro, Cochrane Library, Scopus, and Web of Science databases. Only randomized controlled trials (RCTs) involving patients ≥18 years of age were included. The risk of bias in the included studies was assessed using "the Cochrane Collaboration's tool for assessing risk of bias" (RoB) and the inter-rater agreement for full-text selection was evaluated using Cohen's Kappa (K). The search elicited a total of 4.537 records, and two RCTs involving a total of 196 participants were identified through a selection process based on title, abstract, and full-text assessment. Both studies had a low to moderate risk of bias. The inter-examiner concordance index for the selection of full text was excellent (K=1). RT seems to be an effective and safe intervention for patients with LBLP, but its long-term effectiveness, superiority over other types of exercise-based therapies, and optimal dosage still constitute a gray area in the literature.