A Kalmia fine sandy loam having a pH of 4.5 on which crinkle leaf of cotton occurred in the field was studied in the laboratory and greenhouse.An application of CaCO3 and Na2CO3 to the soil prevented the occurrence of crinkle leaf, whereas the addition of a neutral calcium salt did not prevent the abnormality. Water‐soluble manganese in the soil was greatly reduced by CaCO3 or Na2CO3; however, these salts had little effect on the amount of exchangeable or reducible manganese. CaCl2 had little or no effect on the abundance of any form of soil manganese.A technique was used that maintained high acidity of the soil solution while controlling the amount of manganese and aluminum in solution. By this technique, the symptoms of crinkle leaf were shown to be the result of a high level of manganese in the soil solution and not because of some other factor associated with high soil acidity.Crinkle leaf of cotton can be expected as sufficient acidity develops in those soils that have a high potential supplying power of soluble manganese. The necessary preventive measure for crinkle leaf in the field is an adequate liming program.