Objective Primary aldosteronism (PA) is the most common endocrine form of arterial hypertension. The German Conn’s Registry’s purpose is to improve treatment outcomes of PA. We assessed whether key clinical, biochemical and epidemiological characteristics of newly diagnosed PA cases have changed over time, potentially indicating a different screening and referral practice in Germany evolving from 2008 to 2016. Design The German Conn’s Registry is a multicenter database prospectively analyzing morbidity and long-term outcome of patients with PA. Methods Phenotypic changes between three year periods were calculated using Mann–Whitney U tests and Kruskal–Wallis tests for independent variables. Results Over three time periods from 2008 to 2016, we noted a relative decrease of unilateral PA cases (67 vs 43%). Significantly more females were diagnosed with PA (33 vs 43%). Median daily defined drug doses decreased (3.1 vs 2.0) in the presence of unchanged SBP (150 vs 150 mmHg), plasma aldosterone (199 vs 173 ng/L) and PRC (3.2 vs 3.2 U/L). Median ARR values decreased (70 vs 47 ng/U) and median potassium levels at diagnosis (3.5 vs 3.7 mmol/L) increased as the percentage of normokalemic patients (25 vs 41%), indicating milder forms of PA. Conclusions Our results are in accordance with an increased screening intensity for PA. We identified a trend toward diagnosing milder forms, increasingly more females and less unilateral cases of PA.