A self-sealing male Luer connector for connection with a female Luer connector. The male Luer connector includes a housing having a distally-projecting tubular male body and a surrounding cuff interconnected by a proximal wall in which is formed at least one activation opening. A valve plug is slidably installed within the housing and formed with a distal end configured to sealingly engage the distal end of the male body's interior flow passage and with at least one activation arm at its proximal end configured to extend through the activation opening into the cavity formed between the male body and the cuff. An elastomeric device is sealingly configured within the activation opening about the activation arm to secure the valve plug in position and bias it distally. The proximal end of the male Luer connector may be configured as a conventional female connector, a blood collection device, or other such device.