Adams sang with English National Opera many times, beginning in 1985 as Dikoj in "Katya Kabanova", Mozart's Bartolo in 1991 and 1993 ("the only truly rounded, Mozart-size performance is the Dr Bartolo of the immortal Donald Adams"), Pooh-Bah in "The Mikado", Alcindoro/Benoit in "La bohème" in 1991, the Woodcutter in "Königskinder" in 1992, Mumlal in "The Two Widows" in 1993, Quince in "A Midsummer Night's Dream" in 1995, and "Don Pasquale" (1996). For Welsh National Opera, between 1985 and 1987, he appeared as Monterone in "Rigoletto", Zeta in "The Merry Widow" and the Theatre Director and the Banker in "Lulu". His Baron Ochs in "Der Rosenkavalier" (1990) for WNO was described by "The Independent" as "a triumph for the singer, now 62 years of age, and no longer in his finest or freshest voice, but who made up for any vocal deficiency by the marvellously subtle way he handled the text".