Katie Leach said she was given the handwritten note by two women in their "late 50s or early 60s" at a restaurant in Nampa, America.
She was with her 10-month-old son Drew at the time and said yelling was his "new thing".
The note read: "Thank you for ruining our dinner with your screaming kid! Sincerely, the table behind you."
Leach uploaded a photo of the note to Facebook, but has since removed the Facebook post.
Speaking to American news site KTUB Leach admitted her son had been making noise in the Texas Roadhouse restaurant,, but she added he was not yelling from being upset. He was just excited and she did try to get him to quieten down.
"[Drew] will yell when I tell him no, when he's super excited and happy or just for no reason at all," she said.
"I'm doing my best to teach him indoor voice and to not yell back at me when telling him no etc. but he is only 10 months and learning."
Leach said halfway through dinner, the two women put the note on her table and then sat back down.
Leach told KTVB she approached the women to explain her son was young and learning, but she alleges they said their grandchildren "never behave like that".
The manager of the restaurant told the two women they could finish their dinner, but then had to leave quietly and apologise to Leach for how she was treated.
Travis Doster, a spokesman for Texas Roadhouse, told KBTV: "We’re in the hospitality business. We want all our guests to have a great experience. We are proud to be loud.
"If you want to hear clinking wine glasses and clinking forks, then this probably isn’t the place for you."