In the last few years, causative genes have been identified for most of the familial hyperparathyroidism conditions. Germline mutations in the tumour suppressors multiple endocrine neoplasia type 1 (MEN1) and hyperparathyroidism 2 (HRPT2) provide a molecular diagnosis of multiple endocrine neoplasia type 1 and hyperparathyroidism jaw tumour syndrome, respectively. Germline mutations in the proto-oncogene RET (rearranged during transfection) provide a molecular diagnosis of multiple endocrine neoplasia type 2. Germline mutations of both MEN1 and, less frequently HRPT2, have been found in familial isolated hyperparathyroidism. A molecular diagnosis can now be incorporated into the management of patients with these conditions, however, the ease of diagnostics and value of genetic information in the context of clinical screening and early surgical intervention varies between these disorders. This review focuses on familial hyperparathyroidism and its known causative genes in the setting of neoplastic syndromes, with particular discussion of recent developments in the molecular diagnosis of parathyroid carcinoma.