Background and Objectives: Psoriasis is a chronic, long-term, incurable skin inflammatory disease characterized by the excessive proliferation of epidermal keratinocytes, dilation of blood vessels, thickening of the skin, and the formation of visible red patches of variable sizes. The impact on patients differs with the severity of the disease, leading to physiological discomfort and psychological distress, which significantly affect the quality of life. The etiology of psoriasis is not completely clear, but immune cells, including type 1 and type 17 cytokine-producing cells modulated by regulatory T cells (Tregs), play a critical role in driving the disease pathogenesis. With the ability to specifically target inflammatory markers, biologics can efficiently inhibit the spread of inflammation to achieve therapeutic effects. The goal was to explore the changes in body image and quality of life in psoriasis patients undertaking therapies with biologic agents. Materials and Methods: This study employed a quasi-experimental, single-sample, pretest–posttest design. Forty-four psoriasis patients were recruited from the dermatology outpatient clinics at two medical centers in northern Taiwan. A structured questionnaire, including demographic information, the Body Image Scale (BIS), and the Dermatology Life Quality Index (DLQI), was used as a research tool. Questionnaire assessments were conducted both before and three months after the biologic agent intervention. Statistical analyses were performed using SPSS version 22.0. Results: Our results indicated a significant difference in body image between psoriasis patients before and after intervention with biologic agents. In addition, overall quality of life (QoL) also showed significant improvements before and after biologic agent intervention. There was a positive correlation between body image and quality of life in psoriasis patients. Conclusions: The treatment for psoriasis has evolved rapidly in recent years, and biologic agents have proven to be effective therapies to improve the quality of life for psoriasis patients. Our study suggests that health-related education and psychological support can further benefit psoriasis patients to willingly and positively undertake treatment and therefore improve their positive body image and quality of life.