Best of all, the primary hyperparathyroidism (PHPT) should already be disclosed in the asymptomatic stage. The authors of this contribution are participating in a longitudinal study, which is focused on several aspects of asymptomatic PHPT. The study has been in progress in the Czech Republic at the two tertiary endocrinology centers. Previously we had attempted to verify the assumption that the presence of a chronic disease results in more frequent contact of the patient with the health-care establishment, and that more frequent visits to the consulting room increase the probability of a laboratory examination, and therefore also the earlier detection of PHPT. This time we were particularly interested in a 6-month period before diagnosis of asymptomatic PHPT was completed, wanted to know what the original disease was and whether the contact with the physician increased the likelihood of early diagnosis of PHPT in its asymptomatic stage. At the end of 2010 our cohort included 167 patients aged 2087 years (median 63) who were followed-up for asymptomatic PHPT for 396 months (median 30). The most common concomitant illness was that of endocrine. Out of 118 probands 96 cases suffered from thyroid disease and 10 from pituitary respectively. Seventy-nine patients had cardiovascular disorders; out of them 61 were hypertensive. Twenty patients were followed-up because of malignancy. We were not able to confirm that repeated contact of patients with their physician resulted in earlier detection of PHPT. In 47 PHPT patients, the diagnosis was the result of the search for the cause of osteoporosis. Almost every endocrinologist checked the parathyroid hormone level as a part of endocrinological examination. Surprisingly late PHPT was diagnosed in patients with malignancies. Hyperparathyroidism has been probably a far more common disease than it was previously expected.