The effect of ambient gas on the dynamics of the plasma generated by laser ablation of a carbon target using 1.06 &mgr;m radiation from a Q-switched Nd:YAG laser has been investigated using a spectroscopic technique. The emission characteristics of the carbon plasma produced in argon, helium and air atmospheres are found to depend strongly on the nature and pressure of the surrounding gas. It has been observed that hotter and denser plasmas are formed in an argon atmosphere rather than in helium or air as an ambient. ©1998 American Institute of Physics.