BACKGROUND: Sickle cell diseases (SCDs) are chronic inflammatory processes on capillary level. We tried to understand whether or not there are some positive correlations between acute chest syndrome (ACS) and severity of SCDs. METHODS: All patients with the SCDs were taken into the study. RESULTS: The study included 337 cases (167 females). There were 15 patients (4.4%) with the ACS. The mean ages were similar in both groups (29.4 versus 29.7 years in the ACS group and other, respectively, P > 0.05). The female ratios were similar in both groups, too (60.0% versus 49.0%, respectively, P > 0.05). Additionally, prevalences of associated thalassemia minors were similar in them (66.6% versus 65.5%, respectively, P > 0.05). Smoking was higher in the ACS group (20.0% versus 13.9%), but the difference was nonsignificant (P > 0.05). Although the mean white blood cell count and hematocrit value of peripheric blood were higher in the ACS group, the mean platelet count was lower in them, but the differences were nonsignificant again (P > 0.05 for all). On the other hand, although the painful crises per year, tonsilectomy, priapism, ileus, digital clubbing, pulmonary hypertension, rheumatic heart disease, cirrhosis, stroke, and mortality were higher in the ACS group, the difference was only significant for the stroke (P < 0.05), probably due to the small sample size of the ACS group. CONCLUSION: SCDs are chronic destructive processes on capillaries iniatiating at birth, and terminate with early organ failures in life. Probably ACS is one of the terminal consequences of the inflammatory processes that may indicate shortened survival in such patients.