Objective: Abstracts from the conference should contain enough information about the study to serve as an accurate representation of the process and results, providing optimal information about the research in the limited space that is intended for an abstract. Research presented as conference abstracts should be published in full text in scientific journals for the scientific community to receive detailed information about the conducted research. Previous studies have shown that conference abstracts of randomized controlled trials (RCT) are not necessarily well-written according to the guidelines, but also that publishing of these results as the full text in the journals is not necessary, and that there may be discordances in results between a full text and a conference abstract. Methods: Abstracts presented at the 14th World Congress on Pain in Milan, Italy (2012) were analyzed. All abstracts of selected WCP were searched in order to find those that describe RCTs. Full texts that correspond those conference abstracts were searched on electronic web site of PubMed for MEDLINE database and Google Scholar. Also, all summaries of RCTs from the conference were evaluated according to all 17 items of CONSORT checklist for conference abstracts. Results: Of 119 abstracts of RCTs, within four years of their presentation on congress, only 52% of them were published in the form of full-text research manuscripts in scientific journals. In most pairs of abstracts and scientific manuscripts, numbers of included participants did not match. Between pairs of abstracts and scientific manuscripts, a series of discrepancies related to results were identified. In one third of these pairs, differences in the results were observed, that were mostly quantitative. By analysing all abstracts of RCTs of the conference it was concluded that none of the 119 conference abstracts satisfied all recommendations of the CONSORT guidelines for abstracts, and the authors did not follow most of the 17 domains of these guidelines. Conclusion: Insufficient publication of the results of RCTs presented at the World Congress of Pain and discrepancies between the presented abstracts and their matching publications are important problem in clinical practice because clinicians can get improper or incorrect data, depending on which sources of information they analyze. Conference abstracts do not necessarily follow the guidelines for their writing, which reduces their quality and domain of information that reader gets. Observed problems should be tackled by raising awareness about these issues among researchers and organizers of scientific conferences.