The parts of jawbones and selected teeth (malleolus) of adult marine benthic fish Sparus aurata and Diplodus sargus was collected from different station during east Adriatic coast (Croatia). Biominerals were prepared for three different instrumental analyses: elemental analysis by X-ray Fluorescence (XRF) and inductively coupled plasma spectroscopy (ICP-AES); mineralogical analysis by X-ray diffraction (XRD).The XRF results showed major and traces elements incorporated in the fish teeth. The concentration of zinc (Zn) expressed in mg kg-1 in the enamel - outside part of the malleolus dental surface (teeth crown) varied from 77 up to 1.975 in both fish species. In the root of the same teeth samples of Zn concentration was lower and amounted from 77 - 153 mg kg-1. Contrary, maximal amount of strontium (Sr) was registered in the teeth root from 801 – 1.310 mg kg-1, and in the enamel 476 – 1.104 mg kg-1 respectively. Multivariate statistical analysis based on the Statistica 6.0. PCA has been used to determine differences among elemental composition of the major and trace elements in teeth enamel (crown) and teeth roots, and in examining correlation among incorporated elements and environmental characteristics of the sampling localities.The XRD patterns of both fish jawbones and malleolus teeth showed characteristic hydroxyapatite lines (HAP). The HAP lines of the fish jawbones are broadened and shifted on the higher angles, indicating that mandible and maxilla biominerals are not fully formed and that mineralization of the fish jawbones is a dynamic process that last permanently during organism growth.Selected elements contents Ni, Co, Fe, Cu, and Cr (expressed in mg kg-1) of bulk fishbone samples was determined by ICP-AES analysis. Investigated metals showed higher values in the teeth than in the fish jawbones. The results revealed the distribution of the heavy metals in teeth to be Fe > Cr > Cu > Ni > Co, and in the jaws Fe > Cr > Cu > Ni > Co.The purpose of this study was to investigate the possibility of using XRF for the routine determination of heavy metals in the fish biominerals, in biomonitoring studies and ecological evaluation of the environment. The over-all data obtained indicated that XRF and ICP-AES showed good agreement for the determination of the heavy metals in test samples and that XRF could be used as cost effective method of accurately and precisely determining heavy metals content of the biomineral, while drastically reducing analysis time for initial sample preparation.