The function of populations of nociceptors in muscle pain syndromes remain poorly understood. We compared the contribution of two major classes, isolectin B4-positive (IB4(+)) and IB4-negative (IB4(–)) nociceptors, in acute and chronic inflammatory and ergonomic muscle pain. Baseline mechanical nociceptive threshold was assessed in the gastrocnemius muscle of rats treated with IB4-saporin, which selectively destroys IB4(+) nociceptors. Rats were then submitted to models of acute inflammatory (intramuscular carrageenan)- or ergonomic intervention (eccentric exercise or vibration)-induced muscle pain, and each of the three models also evaluated for the transition from acute to chronic pain, manifest as prolongation of prostaglandin E2 (PGE₂)-induced hyperalgesia, after recovery from the hyperalgesia induced by acute inflammation or ergonomic interventions. IB4-saporin treatment did not affect baseline mechanical nociceptive threshold. However, compared to controls, IB4-saporin treated rats exhibited shorter duration mechanical hyperalgesia in all three models and attenuated peak hyperalgesia in the ergonomic pain models. And, IB4-saporin treatment completely prevented prolongation of PGE₂-induced mechanical hyperalgesia. Thus, IB4(+) and IB4(–) neurons contribute to acute muscle hyperalgesia induced by diverse insults. However, only IB4+ nociceptors participate in the long term consequence of acute hyperalgesia.