BackgroundMethodological research into the design, conduct, analysis and reporting of trials is essential to optimise the process. UK specialists in the field have established a set of top priorities in aid of this research. These priorities, however, may not be reflected in the needs of similar research in low- to middle-income countries (LMICs) with different healthcare provision, resources and research infrastructure. The aim of the study was to identify the top priorities for methodological research in LMICs to inform further research and ultimately to improve clinical trials in these regions.MethodsAn online, two-round survey was conducted from December 2016 to April 2017 amongst researchers and methodologists working on trials in LMICs. The first round required participants to suggest between three and six topics which they felt were priorities for trial methodological research in LMICs. The second round invited participants to grade the importance of a compulsory list of topics suggested by four or more individuals, and an optional list of the remaining topics.FindingsRounds 1 and 2 were completed by 412 and 314 participants, respectively. A wide spread of years of experience, discipline, current country of residence, origin of trials training and area of involvement in trials was reported. The topics deemed most important for methodological research were: choosing appropriate outcomes to measure and training of research staff.ConclusionBy presenting these top priorities we have the foundations of a global health trials methodological research agenda which we hope will foster future research in specific areas in order to increase and improve trials in LMICs.Electronic supplementary materialThe online version of this article (10.1186/s13063-018-2440-y) contains supplementary material, which is available to authorized users.