The objective of this study was to determine to what extent Latin American and Caribbean biomedical journals have endorsed and complied with clinical trial registration and reporting guidelines. A search of randomized clinical trials was carried out using the LILACS database. The randomized clinical trials identified through the search were assessed to determine whether trial registration and CONSORT guidance was mentioned. Information regarding endorsement of the ICMJE, trial registration and other reporting guidelines was extracted from the online instructions for authors of the journals included in the study. The search identified 477 references. We assessed a random sample of 240 titles of which 101 were randomized clinical trials published in 56 journals. Trial registration was reported in 19.8% of the randomized clinical trials, 6.9% were prospectively registered and 3% mentioned CONSORT. The ICMJE was mentioned by 68% of the journals and 36% of journals required trial registration. Fewer journals provided advice on reporting guidelines: CONSORT (13%), PRISMA (1.8%), STROBE (1.8%), and the EQUATOR network (3.6%). Wider endorsement of trial registration and adherence to reporting guidelines is necessary in clinical trials conducted in Latin America and the Caribbean.