Peptide toxins that selectively block voltage sensitive calcium channels have contributed enormously to our understanding of the role of specific calcium channels in normal and pathological conditions. Several members of the ω-conotoxin class of calcium channel blockers are currently in clinical trials for chronic pain. While they are particularly efficacious when delivered intrathecally, side effects may limit their usage. Future advances will come with the discovery of new probes for VSCC subtypes, particularly those that are more selective for pain path-ways and disease states.