You have some quoting issues in your post, so I've reposted the whole thing here, along with a solution. I'm in between painting my place so I didn't have much time to make it more efficient, so here's a way to do it that could use some help in the efficiency department:

update: ++ kcott /update

use strict;
use warnings;

use Data::Dumper;

my $completed_courses = [ 
                       {
                         'type' => 'core',
                         'name' => 'Discrete Structures',
                         'title' => 'CS 130'
                       },
                       {
                         'type' => 'core',
                         'name' => 'Intro to Computer Science',
                         'title' => 'CS 140'
                       },
                        {
                         'type' => 'core',
                         'name' => 'C++ Programming',
                         'title' => 'CS 256'
                       }
                  ];

my $schedule = {
               'CS 130 Section 01' => {
                                        Course => 'CS 130',
                                        Time => '8:00 AM - 9:00 AM',
                                        'Class number' => 35465,
                                        Room => '8 302'
                                      },

              'CS 140 Section 01' => {
                                        Course => 'CS 140',
                                        Time => '8:00 AM - 9:00 AM',
                                        'Class number' => 35465,
                                        Room => '8 302'
                                      },
               'CS 256 Section 01' => {
                                        Course => 'CS 256',
                                        Time => '8:00 AM - 9:00 AM',
                                        'Class number' => 35465,
                                        Room => '8 302'
                                      },
              'CS 241 Section 02' => {
                                        Course => 'CS 241',
                                        Time => '8:00 AM - 9:00 AM',
                                        'Class number' => 35465,
                                        Room => '8 302'
                                      },
           };

for my $done (@{ $completed_courses }){
    my $title = $done->{title};
    for my $section (keys %$schedule){
        if ($schedule->{$section}{Course} eq $title){
            delete $schedule->{$section};
        }
    }
}

print Dumper $schedule;
[download]

Output

$VAR1 = {
          'CS 241 Section 02' => {
                                   'Class number' => 35465,
                                   'Room' => '8 302',
                                   'Course' => 'CS 241',
                                   'Time' => '8:00 AM - 9:00 AM'
                                 }
        };
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.