How long does it take for black toenails to go away?

The time it takes for black toenails to go away depends on the cause. If the black toenail is caused by trauma, it may take up to 12 months for the nail to completely grow out and the black discoloration to disappear. If the black toenail is caused by a fungal infection, it may take several months of treatment with antifungal medication for the infection to clear and the black discoloration to go away. In some cases, black toenails may be permanent and may not go away completely.