Objectives To determine the efficacy of wet-cupping for treating persistent nonspecific low back pain. Inclusion criteria included: (a) lower back pain persisting for 4 weeks or more;(b) age 17–68 years; and; (c) current episode of low back pain having at least a 4-week duration. Exclusion criteria included possible spinal pathology (e.g., carcinoma), severe or progressive motor weakness or central disc prolapse, pending litigation (e.g., workplace injury), bleeding disorders (e.g., hemophilia), and current treatment with wet-cupping. In total, 98 patients aged 17–68 years with nonspecific low back pain; 48 were randomly assigned to experimental group and 50 to the control group. Patients in the experimental group were offered to the wet-cupping service and the control group received usual care. Main outcome measures: Three outcomes assessed at baseline and again 3 months following intervention: the McGill Present Pain Index, Oswestry Pain Disability Index, and the Medication Quantification Scale.