Companies that are able to make their employees feel valued and satisfied with their work tend to have a more productive workforce. While companies by and large would probably like to have satisfied employees, not all go about it the right way.

24/7 Wall St. discussed employee satisfaction with Scott Dobroski, a Glassdoor community expert. “The three top drivers of long-term employee satisfaction are company culture, career opportunities, and trust in senior leadership,” Dobroski said. Companies that cannot provide such positive working environments often suffer from low employee morale and become undesirable places to work. Such companies — especially those in competitive fields — may struggle to attract top notch talent.

Glassdoor is a platform for former and current employees to review their companies. It has thousands of reviews on thousands of different companies on its site. On average, companies have a rating of 3.4 out of 5.0 stars. Yet some major companies are rated significantly lower, and the 18 worst have a rating of 2.7 or lower.

To identify the worst companies to work for, 24/7 Wall St. independently examined employee reviews on Glassdoor — this is not a Glassdoor commissioned report.

Click here to see the worst companies to work for.
Click here to see our detailed findings and methodology.