Current growth measurements have been carried out in carbon dioxide for E/N (electric field/gas number density) values between 84*10^-17 and 166*10^-17 V cm² and N values between 4.5*10¹⁷ and 220*10¹⁷ cm^-3. Ionization and attachment coefficients have been obtained which agree with the results of other workers at the lower pressures while the higher pressure results provide new data for carbon dioxide. The results of sparking potential measurements indicate Paschen's Law is obeyed and secondary ionization coefficients have been calculated. A decrease in the initial photoelectric current with increasing E/N and N has been observed.