Solubility and supersolubility curves of trans-butadiene-acid (TBA) in aqueous media were determined from cooling crystallization experiments in the temperature range T = 25-96 degrees C. Metastable zone width Delta T-max was measured at several cooling rates T at a certain saturated concentration. This procedure was repeated with several saturated concentrations. Also the particle size distribution of the final product was measured. From the relation lg T vs lg Delta T-max nucleation characteristics (n and k(N)) were determined. Mass precipitation rate m(N) and nucleation rate N-N were calculated. This latter one shows good agreement with literature data.