Potential benefits of simulations and virtual laboratory exercises in natural sciences have been both theorised and studied recently. This study reports findings from a pilot study on student attitude, motivation and self-efficacy when using the virtual laboratory programme Labster. The programme allows interactive learning about the workflows and procedures of biological and biochemical experiments, the operation of relevant apparatuses, including the ability to adjust parameters, and the production of results. The programme was used as supplement to mandatory laboratory exercises in two undergraduate courses (i. microbiology and ii. pharmaceutical toxicology) at the University of Southern Denmark. With a theoretical basis in motivational theories, students' (n = 73) motivation and attitude towards the virtual exercises were evaluated. After completing virtual laboratory cases, the students felt significantly more confident and comfortable operating laboratory equipment, but they did not feel more motivated to engage in virtual laboratories compared to real laboratories. Teachers observed that students were able to participate in discussions at higher levels than in previous years where the programme was not used. The study concludes that virtual laboratories have the potential to improve students' pre-laboratory preparation.