ResumenSe desarrolló un método multirresiduo para el análisis de plaguicidas en leche mediante el empleo de cromatografía líquida acoplada a espectrometría de masas. Se estudiaron diferentes variaciones al método de extracción QuEChERS utilizando siete diferentes fases extractantes, dos sales amortiguadoras, tres concentraciones de ácido fórmico en la fase extractante y cuatro tiempos de ultrasonido. De los 58 plaguicidas analizados solo tiociclam y tiodicarb presentaron porcentajes de recuperación inferiores al 70%. Los mejores porcentajes de recuperación y menores coeficientes de variación se obtuvieron empleando el buffer de citrato y acetonitrilo con ácido fórmico al 0,5% como extractante. Por otro lado, no se observaron diferencias estadísticas (P > 0,05) a los tiempos de ultrasonido evaluados. Finalmente, se encontró que el método aplicado es preciso y exacto para Palabras clave: alimento, leche, pesticidas, QuEChERS. AbstractIt was developed a multi-residue method for determining pesticides of different physicochemical characteristics presents on milk. The extraction process is based on the QuEChERS method and determination of the compounds was performed using ultra performance liquid chromatography coupled to mass spectrometry. Also, were evaluated seven different phases of extraction, the effect of different times of ultrasound and three concentrations of formic acid on the extraction process. The repeatability of the method results indicated that for most of the compounds showed coefficients of variation below 10%. Furthermore, it was found that there were no statistical differences (P> 0.05) at different times of ultrasound evaluation. Finally, it was found that the developed method is precise and accurate for the analysis of pesticide residues from different chemical groups such as azoles, organophosphorus, benzimidazoles, carbamates, among others.