The mastitis has been identified as the most costly disease in dairy industry. The aim of this study was performed to provide adequate information on the financial loss due to subclinical mastitis in German dairy farms. The data were collected from 12 dairy farms (a total of 7,648 Holstein-Friesian dairy cows) in the Elbe-Elster region, Germany. Their milk composition data were gathered individually once in a month from June 2011 to June 2012. Herde® (Agrosoft GmbH, Germany), a herd management program was used to analyse the data from the economic point of view. The 50,000 somatic cell counts (SCC)/mL of a cut-off value was used to calculate the decrease in milk production emerged in subclinical mastitis. Average figures on an individual basis showed a daily decrease in milk production of 2.98 kg, 5.41 kg and 6.41 kg for cows with 50,001-100,000 SCC/mL, 100,001- 250,000 SCC/mL and over 250,000 SCC/mL, respectively. All the reductions in milk yield were statistically significant by using mixed effect ANOVA and Tukey’s multiple comparison method. Based on the average milk price in the survey period, a single cow according to the aforementioned SCC classification showed a loss of Euro (€) 294.85, € 536.80 and € 634.40 per lactation in gross milk receipts, respectively. On an average herd level, which was 637 dairy cows in this study, a total decrease of gross milk receipts was calculated to be almost € 241,000 per year. This findings show that the milk production begins to reduce over 50,000 SCC/mL, therefore the generally accepted cut-off value of 100,000 SCC/mL for subclinical mastitis should be re-evaluated.