The aim of this study was to evaluate whether Tc-99(m)-tetrofosmin is a suitable agent for parathyroid scintigraphy. Ten patients with hyperparathyroidism and two normal subjects underwent parathyroid scintigraphy with both Tc-99(m)-tetrofosmin and Tl-201. Thyroid image subtraction was performed with Tc-99(m)-pertechnetate. In the 10 patients with hyperparathyroidism, the scintigraphic results were compared with the surgical findings, which showed seven parathyroid adenomas, two parathyroid adenomas with a co-existing thyroid adenoma, and one thyroid carcinoma. Both Tc-99(m)-tetrofosmin and Tl-201 revealed eight true-positive results, one false-negative result and one false-positive result, with concordance in 8 of 10 patients. The image quality with Tc-99(m)-tetrafosmin of both the raw and Tc-99(m)-pertechnetate subtracted images was always superior compared with that with Tl-201. On the basis of the diagnostic results and the favourable dosimetric characteristics, we conclude that Tc-99(m)-tetrofosmin is a suitable agent for parathyroid scintigraphy.