Introduction: While sharing a common causal link, both rheumatoid arthritis (RA) and periodontitis (PD) manifest similar inflammatory responses. With the progression of severity, both diseases result in bone loss. Hence, Ca and Zn, as structural components of the bones, are expected to be altered in saliva and serum in PD and RA respectively. Zinc and calcium concentrations have been studied previously in patients with PD or RA, with PD patients exhibiting increased salivary Ca and decreased Zn concentrations in serum, while RA patients have been reported to express low plasma concentrations of both Zn and Ca. The aim of this study is to evaluate the saliva and serum levels of Ca and Zn in PD patients with or without RA. Methods: Serum and saliva samples were collected from 82 patients from the Faculty of Dentistry, University of Malaya and the University Malaya Medical Centre rheumatoid clinic. Patients were grouped according to their periodontal health and RA status (healthy n=21; PD n=21; RA n=21; RAPD n=19). Results: Zinc concentration in serum was significantly higher (p<0.05) in the PD group (14.54±4.64 μM) compared to the RA group (11.71±2.04 μM), while in saliva samples the zinc concentration in the healthy group (2.07±1.45 μM) was significantly higher (p<0.01) than both the PD (1.59±3.44 μM) and RAPD (0.71±0.54 μM) groups. Calcium concentrations in serum were significantly higher (p<0.01) in the RA group (19.3±4.28 mg/dL) compared to the con-trol (13.38±1.95 mg/dL) and PD groups (12.36±2.9 mg/dL), while calcium concentrations in saliva were significantly higher (p<0.05) in the RA group (5.41±2.25 mg/dL) compared to the other groups (control = 3.18±1.13 mg/dL; PD = 3.41±0.75 mg/dL; RAPD = 3.69±1.25 mg/dL). Conclusion: These results suggest that PD and RA affect serum and salivary Zn and Ca concentrations in the course of PD and RA pathogenesis. Further research in this area could un-cover more links between PD and RA that as of yet have not been explored.