Objective To analyze and summarize the gait characteristics of patients with sciatica, so as to assist with diagnosis and evaluation for such patients in clinic. Methods Forty-three patients with lumbar disc herniation accompanied by siatica were fitted with portable gait analyzer, and required to walk at the self-selected comfortable speed for a distance of 120 m. Forty-three healthy subjects with matched age, gender and body mass index (BMI) were recruited as control. The gait data including 7 spatial-temporal parameters (single-support duration, double-support duration, ratio of single-support duration to double-support duration, duration of gait cycle, step speed, step frequency, step length) and 4 acceleration parameters (pulling acceleration, swing power, ground impact, foot fall) were collected to compare the gait differences between patients and healthy subjects, as well as between affected and healthy limbs of patients. Results The single-support duration, ratio of single-support duration to double-support duration, step speed, step frequency, step length and four acceleration parameters of patients with sciatica were obviously smaller than those of healthy subjects, while the double-support duration of patients with sciatica was increased. The affected limb of patients with sciatica showed a significant decrease in single-support duration, step frequency and all four acceleration parameters but increase in step length as compared to their healthy limbs. Conclusions Patients with sciatica have significant gait abnormalities due to their affected limbs, which influence their walking ability. Portable gait analyzer can be used for objectively characterizing the walking abnormalities of patients, so as to provide additional information for the clinical diagnosis and evaluation.