Training evaluation in research and organisational contexts is vital to ensure informed decisions regarding the value of training. The present study describes the development of a valid and reliable training evaluation inventory (TEI), as it does not exist so far. The objectives were a) to construct an instrument that is theoretically and empirically founded, but at the same time applicable within typical organisational constraints, and b) to include the assessment and perception of training design as a formative evaluation aspect. Based on previous research, ten scales were constructed, covering the training outcome dimensions subjective enjoyment, perceived usefulness, perceived difficulty, subjective knowledge gain, and attitude towards training, as well as the training design dimensions problem-based learning, activation, demonstration, application, and integration. Reliabilities of the scales were satisfactory. Data from two training studies show that the training outcome dimensions were related to external training outcome measures, underlining the validity of the TEI. Two survey samples were used to predict training outcomes based on training design. Demonstration, application, and integration emerged as the most important design dimensions. The TEI is applicable in both training research projects and in organisational contexts. It can be used for formative and summative training evaluation purposes.