We present echelle spectroscopy in the 3550 to 7010 A range for two positions of the Orion Nebula. The data were obtained with the 2.1-m telescope at Observatorio Astronomico Nacional in San Pedro Martir, Baja California. We have measured the intensities of several permitted lines of C(+) , N(+) , N(++) , O(0) , O(+) , Ne(0) , Si(+) , Si(++) which are excited by recombination and fluorescence. We have determined the electron temperature, the electron density and the ionic abundances using different intensity ratios. In particular the O(++) /H(+) abundance obtained by recombination lines is 40% higher than that obtained using forbidden [O III] lines. Moreover the C(++) /H(+) value derived from the recombination C II 4267 line is a factor of two higher than that derived in previous work for the same zone using C III] 1906+1909 collisionally excited lines. We estimate that a moderate value of t(2) = 0.025 +/- 0.015 can account for these discrepancies.