The Morse problem is investigated in relativistic quantum mechanics. PACS numbers: 11.30.Pb, 03.65.Fd, 11.10.Ef Talk at the Brasilian National Meeting on Particles and Fields, October 15 to 19, 2002, Águas de Lindóia-SP, Brazil. To appear in the proceedings, site www.sbf1.if.usp.br/eventos/enfpc/xxiii. Preprint CBPF-NF-006/03, site cbpf.br.