BACKGROUND: Neck pain is common, disabling and costly. The effectiveness of electrotherapy as a physiotherapeutic option remains unclear. This update replaces our 2005 Cochrane review on this topic. OBJECTIVES: To assess whether electrotherapy improves pain, disability, patient satisfaction, and global perceived effect in adults with neck pain. SEARCH STRATEGY: Computer-assisted searches of: CENTRAL, MEDLINE, EMBASE, MANTIS, CINAHL, and ICL, without language restrictions, from their beginning to December 2008; handsearched relevant conference proceedings; consulted content experts. SELECTION CRITERIA: Randomised controlled trials in any language, investigating the effects of electrotherapy, used primarily as unimodal treatment for neck pain. Quasi-RCTs and controlled clinical trials were excluded. DATA COLLECTION AND ANALYSIS: At least two authors independently conducted citation identification, study selection, data abstraction, and risk of bias assessment. We were unable to statistically pool any of the results, but assessed the quality of the evidence using an adapted GRADE approach. MAIN RESULTS: Eighteen small trials (1043 people with neck pain) with 23 comparisons were included. Analysis was limited by trials of varied quality, heterogeneous treatment subtypes and conflicting results. The main findings for reduction of neck pain by treatment with electrotherapeutic modalities are:Very low quality evidence that pulsed electromagnetic field therapy (PEMF), repetitive magnetic stimulation (rMS) and transcutaneous electrical nerve stimulation (TENS) are more effective than placebo.Low quality evidence that permanent magnets (necklace) are not more effective than placebo.Very low quality evidence that modulated galvanic current, iontophoresis and electric muscle stimulation (EMS) are not more effective than placebo.There were only four trials that reported on other outcomes such as function and global perceived effects, but none were of clinical importance. AUTHORS' CONCLUSIONS: We cannot make any definite statements on the efficacy and clinical usefulness of electrotherapy modalities for neck pain. Since the quality of evidence is low or very low, we are uncertain about the estimate of the effect. Further research is very likely to change both the estimate of effect and our confidence in the results. Current evidence for PEMF, rMS, and TENS shows that these modalities might be more effective than placebo but not other interventions. Funding bias should be considered, especially in PEMF studies. Galvanic current, iontophoresis, electric muscle stimulation(EMS), and static magnetic field did not reduce pain or disability. Future trials on these interventions should have larger patient samples and include more precise standardization and description of all treatment characteristics.