Execution time of procedure

In a procedure which has a Select statement execute from 3 to 4 tables then data inserted into a global temporary table. The execution time of procedure hardly 3 - 5 sec. where as its containing SQL statement i.e. select statement when executing in toad its taking atleast 5 - 6 min. So how its possible and what is the logic behind that. one thing the global temporary table have some indexs also.

the main reason is temp table and having index on that. and also displaying in toad might take more time to populate the grid incomparision to SQL*PLUS ,but the time of execution should be the same.