Hi Andreas,   call symput only writes to the macro symbol table once the data step finishes processing. If you trace through your code execution with that knowledge, you'll find that the behaviour you're seeing is valid and predictable.   Cheers,   Andy. ... View more

Hi Archana,   This looks like a job for the retain statement to set up a flag.   How about something like:   data new;   retain delflag; * don't reset this value to missing for every iteration;   set old;   if _n_ eq 1 and var2=0 then delflag="Y"; * check for var2=0 only on the first iteration;     if _n_ gt 1 and delflag="Y" then do;     var3=0;     var4=0;     var5=0;     var6=0; * Set to zeros only if correct condition met;   end; run; ... View more