Background: Secondary hyperparathyroidism, malnutrition and inflammation have been reported to associate with adverse outcomes in dialysis patients. However, little is known about the implications of these conditions for treatment costs. Methods: The cost data of all adult patients who had entered dialysis therapy at Tampere University Hospital between 1991 and 1996 and had remained on dialysis for at least 1 year were collected. Results of measurements of parathyroid hormone (PTH), calcium, phosphorus, albumin and C-reactive protein (CRP) were obtained from the database of the hospital. Results: Patients (n = 109), aged 57.0 ± 14.9 years, included 57% men and 37% diabetics; 62% started on hemodialysis and 38% on peritoneal dialysis. Average daily costs were USD 161 (range 95–360). After controlling for patients’ age, body mass index, gender, dialysis modality and primary renal disease, there was a positive correlation between average CRP and average costs and a negative correlation between albumin and costs. Correlations between mineral metabolism markers and costs were not found, but there was a trend towards lower cost among patients who achieved the Kidney Disease Outcomes Quality Initiative targets of calcium, phosphorus and PTH (USD 145 ± 31) compared with those with nonoptimal levels (USD 165 ± 48; p = 0.095). Costs of patients with at least one in-target PTH measurement were lower than costs of patients with constantly low PTH (USD 148 ± 31 vs. 170 ± 48; p = 0.01). Conclusion: Serum levels of albumin and CRP correlated with dialysis patients’ treatment costs. Achieving the Kidney Disease Outcomes Quality Initiative targets may be associated with lower costs.