Meningococcal infections are important health problems causing high morbidity and mortality. Neisseria meningitidis have 13 serogroups. A, B, C, Y and W135 are the most common causes of invasive disease among those serogroups. The distribution of the serogroups differs according to the geographical regions and the age groups. In this case report, two cases of meningococcemia infected with serogroup C and Y of N.meningitidis rarely seen in our country were presented. First case was a two and a half year-old female patient who has admitted to our pediatric emergency unit with fever and rash spreading from lower extremities to her body. The patient had diffuse purpuric rash with generalized weakness and tendency to sleep at admission. The patient has been suspected as meningococcemia because of the skin rash, tendency to sleep and hypotension. Antibiotics treatment was started immediately and lumber puncture was performed. In blood tests, leukocyte count: 3600/mm(3) (61% neutrophils), hemoglobin: 11.1 g/dl, platelet count: 127.000/mm(3), C-reactive protein: 10 mg/dl, erythrocyte sedimentation rate: 6 mm/hour, prothrombin time: 28.8 seconds (normal value= 11-16), prothrombin activity: 36%, international normalized ratio (INR): 2.13 (normal value= 1-1.5), activated partial thromboplastin time: 57.7 seconds (normal value= 25-35 sec), fibrinogen: 246 mg/di (normal value= 200-400 mg/dl) and in cerebrospinal fluid protein: 21 mg/dl and glucose: 62 mg/dl were found. There were eight cells in the microscopic examination. Skin rashes were increased and the patient became hypotensive. No microorganisms were isolated in blood and cerebrospinal cultures. N.meningitidis serogroup C was isolated from the cerebrospinal fluid of the patient using polymerase chain reaction (PCR). The patient suffered from immune-mediated arthritis in the sixth day of treatment and nonsteroidal anti-inflammatory drugs were given. The patient has recovered with antibiotics, fresh frozen plasma and inotropic treatment. Second case was a 13 year-old male patient who has admitted three days after the first case with a pre-diagnosis of malignancy because of pancytopenia and fever. The patient had generalized weakness and a few petechial purpuric rashes at the facial region at admission. After the admission general status of the patient has worsened rapidly and he has died as a result of cardiovascular arrest. Blood tests in admission showed leukocyte count: 6000/mm(3) (79% neutrophils), hemoglobin: 17.3 mg/dl, platelet count: 16.000/mm(3), C-reactive protein: 8.63 mg/dl, prothrombin time: 92.6 seconds, prothrombin activity: 10%, INR: 6.78, activated partial thromboplastin time: 231.5 seconds. Cerebrospinal fluid obtained from postmortem lumbar puncture showed no growth (protein: 95 mg/dl, glucose: 35 mg/dl) and N.meningitidis serogroup Y was detected by PCR. Two meningococcemia cases caused by two different serogroups which are rarely seen in our region in recent years were presented at the same time period in the same hospital. This case report pointed out that surveillance has a great importance in such diseases.