Abstract. Fruit consumption is increasing around the world, just as its population. The World Health Organization recommends a minimum consumption of fruit 120 kg/person - year. Fruits such as soursop provide nutrients, phytochemicals and antioxidants which are vital to human health, as well as bioactive substances such as vitamin C, flavonoids, anthocyanins and carotenoids, among others. In this research, soursop (Annona muricata L. cv. Elita) fruits were collected at physiological maturity in two production seasons for their physiological (respiration rate, ethylene production and physiological loss of weight) and physico-chemical characterization (pulp, seeds and skin yield, total soluble solids (TSS), total acidity, pH and firmness). We found that ethylene production peaked at day 6 after-harvest, scoring 133.2 μL kg-1 h-1. This parameter was found to increase during postharvest, with peaks on days 4 and 6, coinciding with the climacteric peaks of biphasic respiration, the largest of which reached a value of 186.9 mg CO2 kg-1 h-1. This is probably the starter for the cascade of events that feature the ripening process, among which changes in TSS, acidity and fruit firmness were outstandingly visible. / Resumen. En el mundo, el consumo de frutas es creciente, al igual que la poblacion. La Organizacion Mundial de la Salud recomienda un consumo minimo de 120 kg/persona al ano. Frutas como la guanabana aportan nutrientes, fitoquimicos y antioxidantes de vital importancia para la salud humana, ademas de sustancias bioactivas como vitamina C, flavonoides, antocianinas y carotenoides, entre otros. En la presente investigacion, frutos de guanabana (Annona muricata L. cv. Elita), fueron recolectados en estado de madurez fisiologica o de cosecha, en dos epocas de produccion, para determinar sus caracteristicas fisiologicas (tasa de respiracion, produccion de etileno y perdida fisiologica de peso), y fisico-quimicas (rendimiento en pulpa, semillas y piel, solidos solubles totales (SST), acidez total, pH y firmeza). Se pudo constatar que la produccion de etileno alcanzo un maximo en el dia 6 de la poscosecha, con un valor de 133,2 μL kg-1 h-1. Este parametro presento un comportamiento creciente durante la poscosecha, con picos en los dias 4 y 6, coincidentes con los picos climatericos bifasicos de la respiracion, el mayor de los cuales alcanzo un valor de 186,9 mg de CO2 kg-1 h-1. Esto, probablemente es el activador de la cascada de eventos propios de la maduracion, donde sobresalen los cambios los niveles de solidos solubles totales, acidez y la firmeza de los frutos.