The two germanates K2MgGeO4 and K2CdGeO4 have been synthesized by solid-state reaction. These compounds are isostructural with K2ZnGeO4, space group Pca21 (No. 29), Z=8. Unit cell parameters were determined: for K2MgGeO4a=11.1810(11), b=5.5708(6), c=15.8694(16) Å, V=988.5(3) Å3 and for K2CdGeO4a=11.4777(24), b=5.7155(7), c=16.1732(17) Å, V=1061.0(5) Å3. Powder diffraction data are reported.