A comprehensive review of the reports concerning the synthesis of symmetrical and, particularly, mixed acetals and orthoesters with transition metal compounds and complexes as catalysts is presented. The following methods for the synthesis of symmetric and mixed acetals are discussed: acetalization of alde- hydesorketoneswithalcoholsordiols;transacetalization;synthesisfromvinylandallylethers;synthesis via intra-orintermolecularadditionofOHgrouptoatriplebond;oxidationofprimaryalcohols;tetrahy- dropyranylation of alcohols or phenols; synthesis from epoxides and aldehydes or ketones; formation of 1,3-dioxanes by Prins cyclization of olefins with paraformaldehyde; oxidative cyclization-carbonylation of ynones; acetalization of ene-diol under Wacker-type catalysis. Reviewed is also the synthesis of mixed orthoesters via additionofalcoholsandphenolstoacroleinacetals.Presentedaremethodsoftheisolation of pure products, recycling of the catalysts (if applicable) and the advantages of the metal complexes compared to classical catalysts, Brønsted acids in particular. The relationship between the structure and reactivity was analyzed and the mechanisms of the reactions of acetal formation catalyzed by transition metal compounds and complexes were discussed.