The purpose of this study is to investigate the differences and similarities of quality of life (QoL) in American and Portuguese cancer patients with hematological malignancies as well as the robustness of the measures cross-culturally. Portuguese participants were 98 patients and 49 accompanying persons and the American participants were 55 patients and 22 accompanying persons. Fifty (Portuguese sample) to 40% (American sample) of the patients came with an accompanying person who answered the questionnaire concerning the patient's QoL. The two cultural groups were characterized in terms of QoL (measured by the SF-36 and the FLIC), social support (Social Support Scale), socio-demographic and clinical variables. Portuguese patients reported a higher QoL. However, this result could be attributable to the fact that the two cultural samples differ in socio-economic status. The measures seem to be comparable for the Portuguese and American samples, at least in what concerns reliability and concurrent validity.