The aim of our study was to assess clinical variables with the best correlation to quality of life (QOL) assessed by medical outcome survey Short-Form 36 (SF-36) in patients with spondyloarthritides, including ankylosing spondylitis (AS) and psoriatic arthritis (PsA). We analyzed the cohort of 54 patients (22 patients with PsA and 32 patients with AS), who filled the Croatian version of SF-36. For each type of arthritis, patients were clinically evaluated using the extensive list of clinical variables categorized into subjective and objective group. For AS patients, subjective and objective variables (spinal mobility measurements, clinical assessment of spinal pain, patient assessments of disease activity and pain) correlated mainly with the physical functioning concept of SF-36. Patients assessments of fatigue correlated with the energy/fatigue subscale, whereas patient assessment of enthesial pain correlated with the pain subscale. Correlations between clinical variables and SF-36 concepts of PsA patients showed more diverse distribution than for AS. Objective variables (spinal mobility measurements, a 76-joint score, clinical assessment of spinal pain) correlated with concepts concerning physical health and pain. Several subjective patient assessments correlated with energy/fatigue, emotional well-being, pain and general health subscales. Both patient and physician assessment of PsA activity correlated with the role limitations due to emotional problems. Bath ankylosing spondylitis functional index (BASFI) had the strongest correlation with the physical functioning concept of SF-36 in both diseases. Our findings provide important information to help selecting the variables with strongest impact on QOL, for better planning the management strategies and achieving better rehabilitation results.