PurposeThe aim of the present study was to investigate relationships between sense of coherence, emotion-focused coping, problem-focused coping, coping efficiency, and mental quality of life (QoL) in patients with chronic illness. A model based on Lazarusâ and Folkmanâs stress and coping theory tested the specific hypothesis: Sense of coherence has a direct and indirect effect on mental QoL mediated by emotion-focused coping, problem-focused coping, and coping efficiency in serial adjusted for age, gender, educational level, comorbidity, and economic status.MethodsThe study used a cross-sectional and correlational design. Patients (nâ=â292) with chronic diseases (chronic heart failure, end-stage renal disease, multiple sclerosis, stroke, and Parkinson) completed three questionnaires and provided background data. Data were collected in 2012, and a serial multiple mediator model was tested using PROCESS macro for SPSS.ResultsThe test of the conceptual model confirmed the hypothesis. There was a significant direct and indirect effect of sense of coherence on mental QoL through the three mediators. The model explained 39% of the variance in mental QoL.ConclusionsSelf-perceived effective coping strategies are the most important mediating factors between sense of coherence and QoL in patients with chronic illness, which supports Lazarusâ and Folkmanâs stress and coping theory.