I have had a similar problem a few weeks ago, and it is probably not a Perl problem. I had a shell script connecting to an Oracle database, retrieving some data and then only launching a Perl program to do things with the data. When run from the shell prompt, everything went fine, but it did not work when launched as a cron job. The problem had to do with environment variables necessary to access the Oracle database, which were set properly when working in interactive mode from the ksh or bash prompt, but not set when launched under the cron tab. You probably have to find which environment variables are missing and set them somehow in your script.