Which restaurants do consumers deem the least clean?

A clean restaurant may not be the No. 1 factor in driving repeat traffic. But a dirty establishment can certainly be a way of guaranteeing guests won’t come back.

To compile its Consumer Brand Metrics (CBM) data, Restaurant Business’ sister company Technomic surveys hundreds of diners each quarter. Read on to see which chains CBM survey respondents gave the lowest proportion of high ratings for cleanliness (and, in many cases, the highest proportion of negative ratings), according to Technomic’s data for the past year. The overall ratings, which are organized here by limited service and full service, take into account interior and bathroom cleanliness, as well as the perceived cleanliness of the kitchen and food preparation areas. Full-service and fast-casual restaurant scores also reflect ratings on the cleanliness of servingware.

Quick-service pizza chain Little Caesars fell well below consumers’ average fast-food cleanliness rating of 49.3%, with just 37.9% of diners giving it high marks for tidiness. Little more than a quarter (28.4%) of customers lauded the chain’s bathroom cleanliness. “The workers can be very rude, and the store can be so dirty,” one CBM survey respondent said.

Just 36.8% of consumers offered positive ratings for the overall cleanliness of Church’s Chicken. Meanwhile, the quick-service chicken chain received especially high negative ratings, with 7.2% of consumers giving it the lowest rating for interior cleanliness and 8.2% giving it the lowest marks for bathroom cleanliness. “The lobby was dirty with no clean table,” one respondent wrote. “I had to clean my own.”

Some 8.9% of customers gave Jack in the Box’s bathrooms the lowest-possible ratings for cleanliness, while just 34.7% of consumers rated the chain’s cleanliness highly overall. “The bathrooms were filthy and the restaurant was dirty,” noted one respondent, who gave Jack in the Box a below-average rating.

Just about a third of consumers (33.3%) gave quick-service chain Checker’s high ratings for overall cleanliness, while 8.7% of diners believed it merited the lowest rating for interior cleanliness, and 7.3% rated the bathroom cleanliness negatively.

Though just by a thread, McDonald’s received the smallest proportion of positive scores for cleanliness overall, according to the latest CBM data. Some 33.2% of consumers said the chain deserved praise for overall cleanliness, while 33.1% said the same for interior cleanliness and 32.3% applauded the bathroom cleanliness.

A little under half (49.1%) of consumers gave Chili’s Grill & Bar high marks for cleanliness, below the overall average of 56.8% for full-service chains. The casual-dining brand received its lowest ratings for the cleanliness of its kitchen and food prep areas, with just 43.6% of diners offering praise.

Overall, 47.6% of diners found reason to applaud the cleanliness of Friendly’s, with the chain’s bathrooms receiving positive marks from just 42.9% of consumers. Meanwhile, 5.8% of diners gave the bathrooms at the family-dining chain the lowest-possible scores. “The specific Friendly’s that I went to was very dirty,” said one survey respondent.

Some 47.5% of consumers lauded the overall cleanliness of IHOP. Slightly more (47.8%) gave high marks for the family-dining brand’s interior cleanliness, while just 42.9% praised the tidiness of the kitchen and food prep areas.

Family-dining concept Huddle House didn’t generate rave reviews for cleanliness, with just 44.4% of customers overall considering it very clean. The chain also garnered the highest proportion of negative reviews for a full-service restaurant, with 8.9% of consumers giving the restrooms negative ratings for cleanliness, 6.7% rating the interiors as unclean and 5.8% saying the kitchen area was not tidy. “It was not clean,” said a respondent, who gave Huddle House a poor rating. “Food on floors, dirty tables. Employees didn’t look very hygienic.”

The chain with the lowest proportion of positive consumer ratings for cleanliness is Waffle House, with just 39.5% of diners praising the chain’s overall tidiness. A full 10.4% of diners said the chain’s bathrooms were very unclean (just 35.5% of consumers applauded the bathroom cleanliness), while 7.5% of respondents gave the chain’s interior cleanliness the lowest-possible ratings. “The restaurants are generally very dirty,” one surveyed customer said.