Objective Lower respiratory tract infections (LRTI) are one of the most important causes of morbidity and mortality in childhood. Hypoxemia, pulmonary hypertension (PH) due to pulmonary vasoconstriction, and heart failure due to various causes are the most important risk factors for mortality in LRTI. The aim of this study was to investigate characteristics of the patients with LRTI and the frequency of PH that developed secondary to LRTI. Materials and Methods The study included 70 patients who were diagnosed as having LRTI clinically and radiologically between January 2012 and March 2013 at Department of Pediatrics, Konya Training and Research Hospital. Age, sex, risk factors for LRTI, symptoms and physical examination findings, laboratory tests, and Doppler echocardiography findings of the patients were retrospectively reviewed. Results Of the patients, 44 (62.9%) were male and 26 (37.1%) were female. Thirty-seven (52.9%) patients were younger than 1 year, and the mean age was 2.5 ± 3.11 years. The most common symptoms of the patients were cough and fever. Rhonchus, retraction, and crackles were found to be the most common findings in physical examinations. Heart failure was found in 10% of patients and PH was detected in 8.6% through Doppler echocardiography. Development of heart failure and the presence of bilateral patch infiltration on posteroanterior chest X-rays were significantly more frequent in patients with PH. Some 42.9% of patients had at least one viral agent in their nasopharyngeal swabs. The most common viral agents were respiratory syncytial virus and rhinoviruses. Conclusion PH may develop during the course of LRTI in children. Given that the development of PH can cause life-threatening complications such as heart failure, affected patients should be kept under close follow-up. It should be remembered that PH is more likely to develop in patients with bilateral patch infiltration on chest X-ray.