Antisolvent crystallisation of trans-chalcone was investigated using ethanol as the solvent and water as the antisolvent under both silent and ultrasound-assisted conditions. Solubility, metastable zone width, crystal yield, crystal structure, morphology, and particle size and shape distribution were evaluated. The solubility of trans-chalcone in ethanol increased with temperature, while the metastable zone width increased with initial solute concentration and showed a non-monotonic temperature dependence. Under silent conditions, crystal yield decreased with increasing temperature; therefore, ultrasound-assisted experiments were performed at 30 °C. Ultrasound was applied after the cloud point to examine its post-nucleation influence on recovery and crystal attributes. The yield increased from approximately 50% under silent conditions to approximately 60% at 30 W, then decreased at higher ultrasound powers. PXRD patterns showed no evidence of a major structural transformation, although relative peak intensities varied with ultrasound power. FESEM SE images indicated plate-like crystals with ultrasound-associated surface irregularities (pits), while image-based particle size and shape analysis (using SOPAT) showed only limited size reduction and negligible change in aspect ratio. These results suggest that moderate post-nucleation ultrasound can improve crystal recovery without substantially altering the crystal habit or structure of trans-chalcone under the investigated conditions.