It is perfectly fine as long as BOTH of you are aware of the facts and possible problems that might arise.First you need to be aware that women and men have a different biological clocks ticking. When you are around 25 and she is around 30 you might think that you are too young to start a family. You would rather wait 5u201310 years until your career is more stable.This is ok for a man. But if your wife is 5 years older than you, she will be 30 and may not have another 5u201310 years to have your children (plural). This scenario is quite common and many times it continues like this.Once the couple is ready to start a family (her 35 or older) it may not work as expected. Maybe reproduction clinics can help, maybe not.In the end it is often the man who then looks for a younger woman to have his children while his original wife is left childless and often quite unhappy.On the other hand if you are 25 and see yourself as a grown up man who is ready to start a family now, marriage with a 30 year old woman who may also be more than ready to start a family might be the right thing.The second problem I have seen in such marriages comes from the different way men and women age.You as a man (in our example 25) may not have reached your peak value in the sexual market place. As your career gains momentum it may very well be, that with 30u201335 you will have even better options with the ladies than you have today.Your wife on the other hand (in our example 30) has her 10 best years behind her. Not only her fertility but also her looks are not going to last forever.If she has good genes and takes good care of her body she may have another 10 years or even 15 years to maintain her good looks.You on the other hand might still find the same 25u201330 year old women attractive 30 years from now. And they might be interested in you as well.A divorce in favor of a new and younger woman is much more likely if the wife is older than her husband.As long as these two items are well understood by BOTH OF YOU the marriage can be happy and longlasting nevertheless.