Psoriasis is a chronic skin disorder that affects 1% to 3% of the general population worldwide. Streptococcal infection, especially streptococcal pharyngitis, has been shown to be a significant trigger of psoriasis in some patients, possibly by sensitizing T cells to keratin epitopes in the skin. Due to the role of the palatine tonsils as an immunological organ that may generate autoreactive T cells, tonsillectomy has been investigated as a treatment for psoriasis. Tonsillectomy originally gained acceptance in Japan as a treatment for palmoplantar pustulosis, a condition that shares features with pustular psoriasis. Subsequently, tonsillectomy has been used for the treatment of plaque psoriasis and guttate psoriasis. Recently, the first randomized, controlled clinical trial of tonsillectomy was performed. Here, we review the available evidence for the benefit of tonsillectomy as a treatment for palmoplantar pustulosis and psoriasis. We also discuss molecular studies aimed at understanding the role of tonsils in skin disease.