The works listed here are of three types: those left incomplete; those that were projected but never carried out by Donizetti; and individual numbers mostly from librettos that he had no intention of setting as a whole.

Adelaide. Of the approximately 100 manuscript pages of this score now in the Bibliothèque Nationale, Paris (formerly part of the Malherbe Collection), many were incorporated into L'ange de Nisida and from there some of them found their way into La favorite. The autograph consists of vocal parts, a bass line to indicate harmony, and occasional proposals for instrumentation. Adelaide, an opera semiseria, has a libretto by an unidentified poet, but it is clear from references in the text of the autograph that the plot is to some extent derived from Baculard d'Arnaud's Les amans malheureux, ou Le comte de Comminge (Paris, 1790); it also bears some relation to Gaetano Rossi's libretto for Pacini's semiseria Adelaide e Comingio (Milan, 1818). The list of characters includes Adelaide (soprano), Roberto (tenor), Il Colonello (baritone) and Il Marchese (buffo). Zavadini (Donizetti: Vita – Musiche – Epistolario, p. 178) suggests a date of 1834 for this score, but it could have been composed at any time during the following four years. It is clear from the presence of some of the material in L'ange de Nisida that Donizetti took his unfinished manuscript with him to Paris in 1838.