Cannabinoids have been proposed as a therapeutic alternative for fibromyalgia. However, their clinical effectiveness is a matter of debate.To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies and generated a summary of findings table using the GRADE approach.We identified fifteen systematic reviews including two randomized trials overall. We concluded it is not clear whether cannabinoids have any benefit in fibromyalgia because the certainty of the evidence is very low. On the other hand, they are associated to frequent adverse effects.