We conducted a cross-sectional study from September 2001 to August 2003 during which children between 2 and 12 years of age presenting with complaint of sore throat were recruited from urban pediatric clinics in Brazil, Croatia, Egypt and Latvia. The objective of the study was to compare clinical signs and symptoms of children presenting to urban pediatric clinics with sore throat in and between countries and to identify common clinical criteria predicting group A beta hemolytic streptococcal (GAS) pharyngitis. Using a single standard protocol in all four sites, clinical data were recorded and throat swabs obtained for standard GAS culture in 2040 children. Signs and symptoms were tested for statistical association with GAS positive/negative pharyngitis, and were compared using chi(2) tests, ANOVA and Odds Ratios. Clinical signs of GAS pharyngitis in children presenting to clinics varied significantly between countries, and there were few signs or symptom that could statistically be associated with GAS pharyngitis in all four countries, though several were useful in two or three countries. Our results indicate that the clinical manifestations of pharyngitis in clinics may vary by region. It is therefore critical that clinical decision rules for management of pharyngitis should have local validation.