The structure, resistivity and ESR of a new molecular charge transfer salt β-(salt (BEDT-TTF)4• H2O • Fe(C2O4)3• C6H5NO2(BEDT-TTF = bis (ethylenedithio)tetrathiofulvalene) are studied. The structure of the salt consists of successive layers of BEDT-TTF which are packed according to β-type and layers of approximately hexagonal geometry containing alternating H2O and Fe(C2O4)33−, with C6H5NO2lying within the hexagonal cavity. Its main crystallographic parameters are found to be:M= 1999.6(1),a= 10.31(8),b= 20.14(8),c= 35.34(4) Å,β= 92.21(9)°V= 7342.0(5) Å3, space group C2/c; Z = 4. The conductivity of this salt at room temperature is l0 Scm−1and shows semiconducting behaviour from 20 to 300K. The ESR line width is found to be 38.1 (300 K), which is substantially wider than a typical line width for BEDT-TTF based radical cation salts of theβ-type, indicating a two-dimensional character. The comparison of crystal structure and properties of the title compound with other salts of this family (BEDT-TTF)4• A • Fe(C2O4)3• C6H5NO2, whereA= H2O, K+or NH4+, is also carried out.