Resumen: A modification of Watson''s lemma for Laplace transforms (Formula presented.) was introduced in Nielsen, 1906], deriving a new asymptotic expansion for large (Formula presented.) with the extra property of being convergent as well. Inspired in that idea, in this paper we derive asymptotic expansions of two-dimensional Laplace transforms (Formula presented.) for large (Formula presented.) and (Formula presented.) that are also convergent. The expansions of (Formula presented.) are accompanied by error bounds. Asymptotic and convergent expansions of some special functions are given as illustration. Idioma: Inglés DOI: 10.1080/10652469.2022.2098955 Año: 2023 Publicado en: Integral transforms and special functions 34, 3 (2023), 196-210 ISSN: 1065-2469 Factor impacto JCR: 0.7 (2023) Categ. JCR: MATHEMATICS rank: 218 / 490 = 0.445 (2023) - Q2 - T2 Categ. JCR: MATHEMATICS, APPLIED rank: 237 / 332 = 0.714 (2023) - Q3 - T3 Factor impacto CITESCORE: 2.2 - Analysis (Q2) - Applied Mathematics (Q3)