Multivitamin preparations are used more and more and one attends a tendency toward a merchandising increased of new products to basis of vitamins and mineral salts. The consumption of these products increases because of the deficit in vitamins generated by the new food habits. Otherwise, this consumption grows in a goal of physical and intellectual performance research. Authors propose in the setting of the product control to basis of vitamins and notably water-soluble, method of analysis for the simultaneous dosage of four vitamins [vitamin B1 (Thiamine), B2 (Riboflavin), B6 (Pyridoxine), and PP (Nicotinamide)] by reversed phase HPLC with a detection in UV by a spectrophotometer to biretta of diodes. The method has been clarified after the survey of the four vitamins separation according to the polarity and the pH of the mobile phase. The separation is optimal on phase silica transplanted in C18 and a phase mobile methanol/water 50/50 and to pH 4.5.