By using the Sagdeev pseudopotential method, ion-acoustic solitary waves are studied in a collisionless, unmagnetised single electron-temperature plasma with adiabatic positive and negative ion drifts having equal ion-temperatures (particular case). The effect of ionic temperature and negative ions on solitary waves is discussed for the plasmas having (He+, O-), (He+, Cl-) and (H+, O-) ions.Proučavaju se ionsko-zvučni solitonski valovi u bezsudarnoj nemagnetiziranoj plazmi s jednom elektronskom temperaturom i s adijabatskim pomacima pozitivnih i negativnih iona koji imaju jednu temperaturu (poseban slučaj) primjenom Sagdeeve pseudopotencijalne metode. Razmatra se učinak ionske temperature i negativnih iona na solitonske valove u plazmi s (H...