Skin and soft tissue infections are most commonly caused by staphylococci or streptococci. Rarely, they can develop due to bacteria of the genus Aeromonas after contact with contaminated water and soil following trauma. A 75-year-old female diabetic patient applied to the infectious diseases outpatient clinic with complaints of swelling, pain, redness, tenderness, erythema and warmth in her lower leg. The patient had a skin deformity as a result of a previous traffic accident and she had gone to thermal springs 2 weeks before. Streaking suggestive of lymphangitis, redness, bullous lesions and right lower extremity edema were noted. Leukocyte count was 18 300/mu L (87% neutrophils), C-reactive protein was 26.1 mg/dL, erythrocyte sedimentation rate was 57 mm/h, hemoglobin was 10.3 mg/dL, and albumin was 2.3 gr/dL. Vascular pathology was not detected in the lower extremity venous Doppler examination. In superficial soft tissue ultrasonography examination, diffuse thickening of skin and subcutaneous area, 3x5 cm diameter small fluid collection defined as cellulitis and abscess in the lower right leg were observed. On the second day of admission, Aeromonas hydrophila was isolated from the drainage culture of abscess. Isolated strain was resistant to penicillin, ampicillin and cefazolin, and susceptible to trimethoprim-sulfamethoxazole, ciprofloxacin and second-and third-generation cephalosporins. She was treated with ciprofloxacin 400 mg IV bid and ceftriaxone 2 gr IV qd, and treatment was completed to 14 days. She was discharged from the hospital 16 days after admission with recovery. As noted in this case study, the cellulitis in the setting of soft tissue trauma and exposure to water and soil should alert the clinician regarding the possibility of infection with Aeromonas.