Appendicitis inflicts diagnostic difficulties, particularly in ambiguous morbid symptoms defined in the scale ALVARDO in the section 4-6 pt.The aim of the study was the comparison of the diagnostic values of the classic method of recognizing appendicitis and those improved by ultrasonographic examination.Material and methods. Patients were classified in this investigation according to symptoms from the section compartment 4-6 pt of the ALVARADO scale. Qualification for the treatment was determined according to the medical investigation and laboratory examinations. Ultrasonography (US) was executed in all patients with the aim of the evaluation of the appendix. The percentage of correct recognitions by means of the classic diagnostics was compared to the percentage determined with the aid of US.Results. It was affirmed that in ambiguous clinical cases of appendicitis, the addition of US to the traditional investigational diagnostics improoves the percentage of correct recognitions of appendicitis from 62.8% to 86.2% (p<0.01).Conclusion. With the US supplementing the classic diagnostics, the percentage of correct recognitions of appendicitis enlarges in adult patients with the suspicion of appendicitis with so-called "grey zone" symptoms comprised in the scoring 4-6 pt of the ALVARADO scale.