can you do a chi sq w/ 2 different n sizes?

#1
can you do a chi sq w/ 2 different n sizes? I have an experiment with 2 groups (pre medicine and post medicine).
Group 1: 400 subjects
Group 2: 332.

When Put the data in (via 1 and 0s) into my SPSS I keep getting really weird answers. How can I accommodate for the 68 subject difference??? Thanks :)!
 

Dason

Ambassador to the humans
#2
Well you didn't actually tell us what you're doing?

And were any of the individuals in both the pre-medicine and the post-medicine groups?