Precipitation of LaBO₃ on the surface of a glass of composition 0.1Cr₂O₃·25Li₂O·10La₂O₃·65B₂O₃ (in mol%) was enhanced due to ultrasonic surface treatment (UST) with aqueous and ethanol suspensions of LaBO₃ particles. The aqueous suspension gave a higher efficiency than the ethanol suspension. The crystallites were almost uniform in size distribution, and grew irregularly: increase-decrease-increase in size when heated at 580°C. Preferred growth of (200) was detected. The mechanism of UST enhanced crystallization is proposed.