This chapter addresses the diagnosis and treatment of pigmentation disorders commonly encountered in dermatology, focusing on key disorders based on the location of pigment lesions. It presents considerations for reducing side effects by predicting treatment responses using Fitzpatrick and Baumann skin-type classifications. Key hyperpigmentation disorders include freckles, lentigo, café-au-lait macules, and Becker’s nevus, as well as dermal pigmentation disorders like nevus of Ota and ABNOM. The chapter discusses the utility of diagnostic tools such as Wood’s lamp and dermoscopy, which are essential for distinguishing between epidermal and dermal pigmentation. It also outlines hyperpigmentation treatment methods centered on laser therapies (Q-switched, picosecond) and topical agents, detailing various treatment options based on the cause of each disorder and skin type considerations. Additionally, the chapter covers the diagnosis and diverse treatment strategies for hypopigmentation disorders such as vitiligo and pityriasis alba, providing guidance on selecting appropriate treatment methods.