Galactose-α-1,3-galactose (α-Gal) syndrome is an allergic reaction to red meat caused by a tick bite. We report a case of suspected delayed anaphylaxis caused by beef that manifested 2 days after a tick bite. A 15-year-old girl was asymptomatic after consuming beef, pork, and chicken at a barbecue, but 2 days later, she developed anaphylaxis 5 hr after consuming the same beef and pork at a barbecue. Her specific IgE levels (UA/mL) were 0.62 for beef, 1.48 for pork, and negative for chicken. The patient had 14 cats, had a history of multiple tick bites, and had been bitten by a tick 2 days before the onset of anaphylaxis. The allergen component-specific IgE level was α-Gal 3.61, and both Fel d 2 (cat serum albumin) and Sus s 1 (pork serum albumin) were negative. Since the heated pork challenge test result was negative, beef was considered the cause. Alpha-Gal syndrome can occur in patients with no history of allergic symptoms, induced by the ingestion of red meat, but tick bites can cause delayed anaphylaxis. An early diagnosis and appropriate dietary guidance are thus important.