The magnetic susceptibility χp of powdered FeC2O4.2H2O has been measured between 1.3 and 300°K. Above ~80°K, χp=3.40(T+25.4) (cgs/mole). χp exhibits a broad, rounded maximum near 30°K and a sharp peak at 20°K. X-ray structural evidence indicates that Fe++ions in this material are linked in chains by oxalate groups. Assuming an antiferromagnetic intrachain exchange constant J=-4.9k, it is possible to obtain a reasonable fit of the data above 25°K with the susceptibility computed for Ising interactions and S=2. If the upper maximum is due to chain ordering, the lower maximum then appears to be associated with the cooperative onset of long-range spin order in three dimensions induced by interchain coupling.