A simple and economical system is proposed for prohucing beta-galactosidase with the yeast Kluyveromyces lactis in solid-state fermentations on corn grits or wheat bran moistened with deproteinized milk whey. By means of a full-factorial design, we studied some conditions that improve this production. Results of liquid- and solid-state cultures were compared with the latter proving to be more effective. We have demonstrated that changing from liquid- to solid-state cultures does not promote beta-galactosidase secretion by Kluyveromyces lactis.