The core objective of the present work is to explore the reasons why workers from different employment sectors join training courses to improve their job. To this end we assessed achievement motivation, locus of control and professional qualifications according to the participants’ employment sector. The final sample consisted of 1460 active Spanish workers from four different employment sectors: services, catering, metal construction, and others. Of the sample, 40.1% were male and 59.9% female, with a mean age of 33.3 years (SD = 9.7). The results show that the new scale developed to assess achievement motivation, locus of control and workers’ qualifications presents adequate psychometric characteristics. Statistically significant differences were found in relation to employment sector. The areas studied showed satisfactory levels of workers’ effort and achievement motivation to perform their jobs, though their attitudes toward the training courses as a basis for improving their employability are varied. Workers in the catering sector had higher levels of external attribution and the lowest interest in training. Those in the service sector had higher levels of achievement motivation and effort at work. Future research should develop a joint program covering the public and private sectors for the modification of these beliefs, attitudes and attributions.