I fixed "NumberFormatInfo.NumberDecimalDigits " property to be "0". The control display "0", but the Up & Down button don't work!
Please if you can help...
The problem is that small change by default is set to 0.1. Hence, when you remove the decimal digits it can't iterate the value by 0.1. The solution is to set SmallChange=1 , and RadNumericUpDown will be working as expected.