Optical and optical Stark spectra of the O-0(0) (A) over tilde (2)E-(X) over tilde (2)A(1) band system of a supersonic molecular beam sample of calcium monomethyl, CaCH3, have been recorded. Field free spectroscopic parameters were obtained on fitting the (/K’(R)/ = 1, /k’/ = 0 and 2)-(/K "(R)/ = 1) and the (/K’(R)/ = 0, /K’/ = 1)-(/K "(R)/ = 0) subbands. The branch features were reassigned and a resulting new set of spectroscopic parameters determined. The value of the a-principal axis component of die spin-relation parameter, epsilon(aa)((A) over tilde(2)E), is now consistent with the assumed nature of the low-lying excited electronic states. Dipole moments of 2.62+/-0.03 D and 1.69+/-0.02 D were determined for the (X) over tilde (2)A(1), and (A) over tilde(2)E states. respectively. A simple electrostatic model was adapted to predict dipole moments for CaCH3 and MECH(3).