The yield of γ-rays from the reaction 42Ca(p, γ) 43Sc has been measured as a function of bombarding energy over the range 0.63–3.01 MeV, from 44Ca(p, γ) 45Sc over the range 0.775–4.00 MeV, from 42Ca(p, p'γ) 42Ca over the range 2.24–3.01 MeV, and from 44Ca(p, p'γ) 44Ca over the range 1.90–5.03 MeV. The cross section of the reaction 44Ca(p, n) 44Sc has been measured from threshold to a bombarding energy of 5.05 MeV by observation of the 1157 keV γ-ray associated with the residual 44Sc activity, and the cross section of the reaction 45Sc(p, n) 45Ti has been measured from threshold to a bombarding energy of 4.00 MeV both by observation of the annihilation radiation associated with the residual 45Ti activity and by measurement of the total neutron yield with a wide-angle BF 3 tube and paraffin detector. All these data are compared with statisticalmodel calculations and satisfactory agreement is achieved. Thermonuclear reaction rates for the (p, γ) and (p, n) reactions are calculated for the temperature range 5 × 10 8-10 10K and the significance of these results for explosive nucleosynthesis in stars is discussed.