Background: Systematic reviews require literature searches that are precise, sensitive and often complex. Database-hosting platforms need to facilitate this type of searching in order to minimise errors and the risk of bias in the results. Objectives: The main objective of the study was to create a generic checklist of criteria to assess the ability of host platforms to cope with complex searching, for example, for systematic reviews, and to test the checklist against three host platforms (EBSCOhost, OvidSP and ProQuest). Method: The checklist was developed as usual review work was carried out and through discussion between the two authors. Attributes on the checklist were designated as 'desirable' or 'essential'. The authors tested the checklist independently against three host platforms and graded their performance from 1 (insufficient) to 3 (performs well). Results: Fifty-five desirable or essential attributes were identified for the checklist. None of the platforms performed well for all of the attributes on the checklist. Conclusions: Not all database-hosting platforms are designed for complex searching. Librarians and other decision-makers who work in health research settings need to be aware of the different limitations of host platforms for complex searching when they are making purchasing decisions or training others.