Four radionuclides with electron-capture-based decay schemes have been directly measured by a liquid scintillation coincidence extrapolation technique. 125 I, 192 Ir and 65 Zn were measured as part of international key comparisons held under the auspices of the International Bureau of Weights and Measures (BIPM). The 139 Ce measurements formed part of a regional comparison organized by the Asia Pacific Metrology Programme (APMP). Since 139 Ce decays purely by electron-capture, the basic method is described for this radionuclide. Results and difficulties encountered are discussed and uncertainty budgets are presented.