If you have mushrooms growing in your potted plants, you likely want to remove these interlopers permanently. Not only can mushrooms be aesthetically unappealing in a houseplant, but they also can provide tempting "snacks" for kids and pets, who could get sick from eating them. However, mushrooms are tenacious and you likely will need to take several escalating steps to get rid of them completely.
Clip the tops off the mushrooms. Do this very gently so that you disturb the caps as little as possible. Mushroom caps store spores, so removing them will start to limit the propagation of the fungus. Place the caps in a plastic bag before you dispose of them.
Scrape the top 2 inches of soil out of the pot. This will help remove spores that have already fallen. Place the soil in a sealed plastic bag.
Treat the soil and the plant with a fungicide. Generally you can purchase a fungicide that sprays onto the plant and soil, but check the manufacturer's directions since each fungicide is different. Make sure you keep the plant out of reach of pets and children after treating it with the fungicide. Repeat the treatment for several weeks.
Change the plant's environment. If it is possible without killing the plant, water it less frequently to discourage the growth of the fungus and place the plant in full sun. Make sure it is in a room with good air circulation and cooler temperatures. This will make it harder for the fungus to grow, but monitor your plant carefully since it also may make it harder for the plant to thrive.