The aim of this study was to assess the reliability and validity of the Swedish version (HHI-S) of the Herth Hope Index (HHI), developed by K. Herth. The HHI-S is a 12-item Likert scale, arranged with scores from 1 to 4, where 1 is 'strongly disagree' and 4 is 'strongly agree'. The HHI-S together with the Miller Hope Scale (TMHS) and Beck's Hopelessness Scale (HS-S) were distributed to 85 adults, 40 patients with cancer in palliative care and 45 family members to patients with cancer in palliative care, recruited from four different in- and out-patient oncology clinics. The result showed an internal consistency alpha coefficient of 0.88 for the HHI-S. Concurrent criterion-related validity was assessed by correlating the HHI-S with the TMHS (r = 0.82) and the discriminant validity was assessed by correlating the HHI-S with the HS-S (r = −0.69). A varimax-rotated principal component factor analysis was performed and identified two factors; reconciliation with life situation and religiosity. Although the instrument shows sound reliability and validity, it should be used with care in clinical palliative care settings, because of linguistic, conceptual and cultural difficulties when transferring the instrument into Swedish. The result demands the work of developing an instrument measuring hope, based in the Swedish culture.