This paper documents a study, carried out in the academic year 2003-2004, on fifteen factors that may influence performance on a first year object-oriented programming module. The factors included prior academic experience, prior computer experience, self-perception of programming performance and comfort level on the module and specific cognitive skills. The study found that a student's perception of their understanding of the module had the strongest correlation with programming performance, r=0.76, p‹0.01. In addition, Leaving Certificate (LC) mathematics and science scores were shown to have a strong correlation with performance. A regression module, based upon a student's perception of their understanding of the module, gender, LC mathematics score and comfort level was able to account for 79% of the variance in programming performance results.