A standardized, controlled procedure for preparation of an in-house reference (IHR) preparation of an allergen extract of Candida albicans is described. The procedure, based on previous studies of allergens of C. albicans, is designed to yield a maximum of allergens in optimum extraction conditions and to provide a reference preparation for further extract production. The SDS-PAGE, IgE-immunoblotting, and crossed radioimmunoelectrophoresis (CRIE) analyses showed that the procedure is reproducible with acceptable batch-to-batch variation. The variation in the content of the most important allergens, namely, proteins with molecular weights of 46, 29, and 27 kDa in the pooled final batches, is acceptable (coeff. of variation < 15%), although in the intermediate batches of different strains, the coefficient of variation may occasionally exceed 20%. A comparison with other C. albicans allergen preparations used in our previous studies is also presented. The resulting extract can be used as a reference in further extract production and also in experimental in vitro and in vivo studies.