Two mesogenic dicyanates, 4-cyanatophenyl 4-cyanatobenzoate (1) and 4,4’-dicyanatobi-phenyl (2), were synthesized and cyclotrimerized to form s-triazine thermoset networks. Networks with frozen nematic textures were obtained from 1, and from mixtures of 1 with up to 50% of 2, although pure 2 formed an isotropic network independent of curing conditions. The curing reaction was monitored by infrared spectroscopy and calorimetry. The final conversion of both rigid monomers was approximately 80% from dynamic DSC experiments. On isothermal curing of 1 at 160 degrees C, a liquid crystalline phase appeared after 57% conversion. The nematic/isotropic transition and the glass transition temperature of 1 was measured as a function of conversion. The maximum temperature at which anisotropic networks can be obtained on isothermal curing decreases from 240 to 150 degrees C with increasing reactivity (amount of catalyst) of the reacting system.