Cupriavidus pauculus (formerly CDC Group IVc-2) is a non-ferrnentative, motile, gram-negative bacillus, rarely associated with human infections. It has been isolated from water, water from ultrafiltration systems and bottled mineral water. To date, 19 cases of bacteremia, two cases of peritonitis and one case of tenosynovitis associated with C.pauculus have been reported in English literature. In this paper, we report the first case of C.pauculus ventilator-associated pneumonia (VAP) in Turkey. A 47 years-old female with breast cancer was performed total mastectomy six years ago and received six cures of chemotherapy after surgery. The patient was hospitalized in medical oncology clinic with complaints of weight loss, nausea and vomiting for one year, Since she had problems of consiousness, dysphagia and pitosis, lumbar puncture was performed to rule out central nervous systern infection or metastasis. Cryptococcal meningitis was diagnosed upon the examination of Indian-ink stained smear of cerebrospinal fluid and amphotericin B was initiated. On the 11 1h day of her follow up, she developed respiratory distress and was transferred to pulmonary intensive care and underwent invasive mechanical ventilator (IMV) therapy. On the 4 1h day of IMV, a new infiltration was detected on the upper zone of chest X-ray in addition to fever (38.3'C) and intense enclotracheal secretion. Therefore, bronchoscopic examination was performed and bronchoalveolar lavage and bronchoscope aspiration materials were obtained and cultivated. Bacteria grown at blood agar and EMB agar after 48 hours of incubation were stained as gramnegative bacilli and identified as C.pauculus by VITEK 2 compact system (bioWrieux Inc, USA). The strain was susceptible to ceftaziclime, ciprofloxacin, imipenem, trimcthoprim-sulfamethoxazole, piperacilin/tazobactam and resistant to amikacin. The case was considered as C.pauculus VAP and imipenem (500 mg, 4 x 1) for 14 days was initiated. Clinical and micro bi olog ical resolution was achieved by imipenem therapy. In conclusion, rare pathogens like C.pauculus should be considered among the possible causative agents in infections that develop in immunocompromised host.