A 48-year-old woman who worked as a cleaner in a Kashan University of Medical Sciences dormitory received a spider bite while collecting garbage on a summer afternoon. She feltimmediate irritation on her arm. She noticed a spider, which she removed and killed. The irritation, itching, and redness on her arm continued. Her hand became edematous and painful after four days and she suffered from insomnia. Her situation became worse to the extent that she was not able to move her fingers.The patient was hospitalized at Shahid Beheshti Hospital for four days due to the seriousness of her condition. During hospitalization, she received treatments that consisted of normalsaline, corticosteroids, antibiotics, antihistamines, and analgesics after performance of any relevant tests. A tetanus vaccine and tetabulin were also prescribed. She had complaints of ongoing pain, swelling, itching, and redness for four days after which the patient was discharged with a prescription. The spider parts were sent to the laboratory for species analysis. The laboratory results diagnosed this spider as a member of the Loxosceles species. In most cases the cause of the bite disappears and is rarely detected. Here, although damaged, the laboratory could identify the spider.