Yes, pothos is toxic. This is because they have calcium oxalate crystals. Like tiny shards of glass, they can pierce the skin and cause irritation in the mouth or digestive tract if consumed. For this reason, it’s best to keep them away from pets and children. Learn more about pets and toxic plants here. Note: While they are toxic, they're not fatal. They cause irritation to the skin, lips, and mouth as well as cause vomiting.