The fertilizing capacity of pure, fresh avian semen may disappear in just half an hour, hindering its successful use in artificial insemination (AI) projects. Longer storage requires the use of infra-physiological temperatures and of semen diluents that help preserve the spermatozoa but that do not interfere with their fertilizing capacity. This study examines the effect on sperm quality of storing red-legged partridge sperm for 3 h at 5°C with 2 different semen extenders: 1) a medium referred to as L&R-84, composed of sodium glutamate, glucose, magnesium acetate, potassium acetate, and polyvinylpyrrolidone, and 2) Lake 7.1 medium, composed of sodium glutamate, glucose, magnesium acetate, potassium citrate, and N,N-Bis(2-hydroxyethyl)taurine (BES). Extending with L&R-84 returned better curvilinear velocity (P < 0.01), straight-line velocity (P < 0.01), average path velocity (P < 0.01), linearity (P < 0.05), straightness (P < 0.05), and wobble (P < 0.05) values, while extending with the Lake 7.1 medium was associated with higher percentages (P < 0.001) of motile sperm. The fertility rate was higher (P < 0.05) when birds were inseminated with L&R-84-extended sperm than with Lake 7.1-extended sperm. The mean number of penetrations of perivitelline layer samples (taken from above the germinal disc) was also higher for the L&R-84-extended sperm (P < 0.05). These results show L&R-84 can be recommended as an extender for red-legged partridge semen to be stored for at least 3 h at 5°C.