BACKGROUND In view of the claims and counter-claims of the effectiveness of transcutaneous electrical nerve stimulation, it would seem appropriate to systematically review the literature. OBJECTIVE To determine the effectiveness of transcutaneous electrical nerve stimulation in reducing pain and improving range of movement in patients with chronic low back pain. METHODS Electronic searches of EMBASE, MEDLINE, CISCOM, AMED for all studies of TENS in the English language, identifying those treating chronic low back pain and hand searching their references. METHODS The inclusion criterion for studies included in this review, 6 of 68 identified, was comparisons of TENS/ALTENS versus placebo in patients with chronic low back pain. METHODS Outcome data on pain reduction, range of movement, functional status and work was extracted by two independent reviewers together with trial design qualities to construct a Quality Index. RESULTS The ratio of odds of improvement in pain for each comparison was calculated: TENS vs. placebo at 1.62 (95% CI 0.90, 2.68); ALTENS vs. placebo at 7.22 (95% CI 2.60, 20.01) and TENS/ALTENS vs. placebo at 2.11 (95% CI 1.32, 3.38) times that of placebo. An improvement in pain reduction was seen in 45.80% (CI 37.00%, 55.00%) of TENS; 86.70% (CI 80.00%, 93.00%) of ALTENS; 54.00% (CI 46.20%, 61.80%) of TENS/ ALTENS and 36.40% (95%CI 28.40%, 44.40%) of placebo subjects. The odds of improvement in range of movement on ALTENS vs. placebo was 6.61 times (95% CI 2.36, 18.55) that of placebo. CONCLUSIONS Transcutaneous electrical nerve stimulation appears to reduce pain and improve the range of movement in chronic low back pain subjects. A definitive randomised controlled study of ALTENS, TENS, placebo/no treatment controls, of sufficient power, is needed to confirm these findings.