Methodological choices in animal experimentation are influenced by a variety of factors. The analysis of the relative weight of such factors on the practice of animal experimentation can offer a better idea of the influences characterizing the work of researchers today. To this aim, we conducted structured interviews and sent out questionnaires to researchers using animal models. The results showed that the main factor influencing the researchers’ work with animals was the appropriateness of the chosen animal model to respond to the question addressed. Ethical issues came as the next important factor, mostly based on considerations regarding animal suffering. The general public opinion appeared to be of little significance, indicating that a gap still exists between animal researchers and society. This paper shows animal experimentation is influenced by both external (e.g., adherence to scientific objectivity) and internal factors (e.g., ethical concerns), providing a varied profile of the contemporary animal researcher.