The major purpose of this study was to investigate if increasing milking frequency for a short period of 3 weeks had any effects on the persistency of milk yield and the persistency of the somatic cell score (SCS). The methyl green–pyronin method was used for the direct microscopic SCS, converted to SCS for the analyses. Two groups were formed (control, n = 14 and treatment, n = 14). The treatment group was milked four times a day for 3 weeks after weaning. Both groups were milked twice a day outside this 3-week period, throughout lactation. For the milk yield, persistencies were higher in the treatment group when the distance between the test days was equal to or less than 3 months. The exact opposite was true for the SCS; that is, the treatment group had higher persistencies when the distance between the test days was more than 3 months. Overall, persistencies related to milk yield were higher than persistencies related to SCS. For fat corrected milk yield, treatment persistencies were always higher than the control group persistencies, regardless of the distance between the tests. The same was true for the fat content. Increasing milking frequency for a short period of time (3 weeks) after weaning may help to increase the persistency of the milk yield, fat corrected milk yield and fat content. A 3-D plot of least squares means indicated that the milk yield tended to show a classical lactation curve in lower SCS values while forming an unstable curve in higher SCS values.