Objective: Fear of progression (FoP) is a frequent symptom among cancer patients, but data among hematological cancer survivors are scarce. Furthermore, theory assumes that FoP serves as link between bodily symptoms and different aspects of quality of life. However, this model has not been tested with the bodily symptom cancer-related fatigue (CRF) so far. Therefore, we investigated (i) levels of FoP stratified by type of and time since diagnosis and (ii) whether FoP mediates relationships of CRF with physical functioning (PF) and global quality of life (QoL). Methods: This cross-sectional study recruited long-term survivors of hematological malignancies (mean time since diagnosis: 9 years) via two regional cancer registries. We applied analyses of (co-)variance and mediation analyses to identify indirect effects. Results: 922 survivors participated. There was no overall effect of type of diagnosis on FoP (Fconditional = 1.6, p = .15). However, we found an overall effect of time since diagnosis on FoP (Fconditional = 8.5, p < .001), with FoP being significantly elevated in the group closest to diagnosis. As hypothesized, we found an indirect (mediating) effect of FoP in the associations of CRF with QoL (β = −0.13, 97.5 %-CI = [−0.17; −0.09]) and PF (β = −0.12, 97.5 %-CI = [−0.17; −0.08]). Conclusion: Among long-term survivors of hematological malignancies, a shorter time since diagnosis seems to be associated with elevated levels of FoP. Addressing FoP in psycho-oncological interventions may help to buffer the detrimental effects of CRF. However, longitudinal data is needed to validate our findings.