What's the context? are you getting a specific error or running into a problem?

There is no effective limit to a SAS program (they're called programs, not scripts). For example, I recently generated a sas program (using sas) that was 13,000+ lines of code. I don't think there's an effective limit on program size, since most SAS programs typically have a number of discrete steps. The only practical limit would be something like memory. For example, if you were doing a PROC SORT on an inordinately large dataset, you might run into memory constraints.

There are, on varying platforms, different default Line sizes for SAS programs, which might cause a program with very long lines to get truncated.