The short answer is it depends.
If you only need a small photo (standard 6X4″ 10X15cms) then generally the photo will come out ok. If you need this photo enlarged it depends on the quality of the file as to how clear it will be printed. As a general rule of thumb if you have a decent quality file you can print about 1.5 – 2  times larger before you start to see too much loss of quality.
The best thing to do is send me your file and I can advise you on your options.
Please see photographic printing for more information.