Anidulafungin is a semisynthetic antifungal agent which is an echinocandin. Here, we presented elderly patient developed reversible severe thrombocytopenia due to anidulafungin. A 75-year-old man was admitted to the ICU with signs of hypovolemic shock and acute anemia. Amikacin therapy 15 mg/kg/day was started with the diagnosis of pneumonia due to the growth Acinetobacter baumannii. Amikacin therapy was discontinued in the treatment day 3 and began to colistin 2 mg/kg every 8 hours and imipenem 7 mg/kg every 6 hours. On hospital day 17, fluconazole 200mg/day was added to treatment due to candida albicans growth in blood culture and colistin-imipenem treatment was discontinued in the treatment. Candida albicans produced in control blood culture on floconazole therapy day 5 and the treatment was continued. Because of the increasing procalcitonin and CRP levels, liver enzyme elevation and fever 38.5 Co on fluconazole therapy day 6, anidulafungin therapy 200 mg was switched on fluconazole promptly. The dosage of anidulafungin was continued to 100 mg/day. Platelet counts was found to be six thousands anidulafungin therapy day 4. So treatment was terminated and liposomal amphotericin B treatment was started. Five days after the cessation of treatment with anidulafungin, platelets value was found to be over 100 thousand. Antifungal therapy was discontinued on liposomal amphotericin B therapy day 14, due not to the growth of microorganism in control blood culture. The patient who continue to be treated in intensive care, died due to multiorgan failure at 66 days. In conclusion; clinicians may consider monitoring platelets periodically, particularly in patients with hematologic disorders who use antibiotics and / or antifungal agents.