Abstract One of the main challenges in the field of the molecular materials is the design of molecular-based ferromagnets. My basic strategy along this line consists of assembling ferrimagnetic chains within the crystal lattice in a ferromagnetic fashion. This can be achieved owing to the (almost) limitless flexibility of the molecular chemistry. The chains may be either regular or alternating. Examples of both situations are presented. MnCu(pbaOH) (H2O)3 (pbaOH = 2-hydroxy-1,3-propylenebis(oxamato)) is a regular chain compound ordering ferromagnetically at Te 4.6 K, and MnCu(obbz) . 1H2O (obbz = oxamido-N,N'-bis(2-benzoato)) is an alternating chain compound exhibiting a spontaneous magnetization below Te = 14 K. To get information on the mechanism of the magnetic ordering, a broad spectrum of physical techniques is utilized, including magnetic susceptibility and magnetization measurements, EPR spectroscopy and heat capacity data. The perspectives in this new field are outlined.