Background: We investigated the need for additional professional support and influencing factors in patients (pts) at initiation and in the course of in- and outpatient specialist palliative care (I-SPC/O-SPC). Methods: Pts entering an urban SPC network consecutively completed questionnaires on psychosocial/spiritual problems and support needs within 72 hours (T0) and within the first 6 weeks (T1) of SPC. Hierarchical linear regression analysis investigated the impact of sociodemographic / clinical variables, psychological / physical burden, social support, and SPC setting on support need. Results: 425 pts (70 years, 48% female, 91% cancer, 67% O-SPC) answered T0, and 167 T1. At T0, main problems were related to transportation, usual activities, and dependency (83-89%). At T1, most prevalent problems were again related to transportation, usual activities, and additionally light housework (82-86%). At T0, support need was highest for transportation, light housework, and usual activities (35-41%). Cross-sectional comparisons of SPC settings revealed higher problem scores in O-SPC at T0 (p=.039), but not at T1. Support need was higher in O-SPC at T0 (p<.001), but lower at T1 (p=.039). Longitudinal analyses showed a decrease of support need scores over time, independent from the SPC setting. At T0, higher distress (p=.047), anxiety/depression (p<.001), physical burden (p<.001) and I-SPC (p<.001), were associated with higher support need scores (at T1 only higher distress; p=.037).Conclusion: Need for additional professional psychosocial/spiritual support was identified in up to 40% of pts with higher need at the beginning of OSPC than of ISPC. During SPC, this need decreased in both settings, but got lower in OSPC than in ISPC over time. Psychosocial/spiritual support need was associated with not only with psychological, but also physical burden.