Synthesis, X-ray diffraction analysis, and IR spectroscopy of Sr2[UO2(CH2C(CH3)COO)3]4 · 26H2O (I) and Ba2[UO2(CH2C(CH3)COO)3]4 · 26H2O (II) (CH2C(CH3)COO− is a methacrylate ion) crystals have been performed. The uranium-containing structural units I and II are one-core complexes [UO2(CH2C(CH3)COO)3]−, which belong to the crystallochemical group $$AB_{3}^{{0{\text{1}}}}$$ (А = $${\text{UO}}_{2}^{{2 + }}$$ , B01 = CH2C(CH3)COO−) of uranyl complexes. Is established that the parallel orientation of methacrylate anions of neighboring uranium-containing complexes plays an important structure-forming role in crystals I and II. The bulk layers formed due to the interactions of methacrylate anions contain voids, which are occupied by Sr or Ba cations. Linking of structural fragments into a framework is due to the formation of a system of hydrogen bonds and electrostatic and van der Waals interactions.