The results of the study of the influence of a static magnetic field of 55 ± 3 mT on the growth rates of diamagnetic sodium chlorate crystals in the direction ⟨100⟩ will be presented. Two groups of experiments were performed in the same solution supersaturation range of 0.89−1.78%, the first in zero field conditions, and the second in an applied magnetic field. The results show that crystals nucleated and grown in a static magnetic field have higher mean growth rates in the ⟨100⟩ direction than crystals in a zero field. Also, X-ray analyses suggest that crystals nucleated and grown in a magnetic field may have a higher lattice constant. Possible mechanisms and possible reasons for these phenomena are discussed.