Background. When a given option is presented along with 2 alternatives, similar to each other, health care professionals choose it more often than when it is presented with just one of the alternatives. This inconsistent decision pattern may depend on the conflict generated from choosing between 2 highly similar options. Objective. To generalize the effect by using realistic scenarios that involve 2 alternatives displaying various degrees of similarity. Methods. One hundred fifty-five psychiatrists, 149 gynecologists, and 89 nurse managers had to indicate the treatment they would recommend in clinical scenarios containing either 3 options or just 2 of them. The similarity between the 2 alternatives varied across scenarios, ranging from a very high (psychiatric scenario) to an only moderately high (nursing management scenario) to a limited level (gynecological scenario). Results. Professionals chose the focal option more often when both alternatives were available. The paradoxical effect occurred for all scenarios-namely, when the alternatives were medication variants (psychiatric scenario), when most of the features they shared produced their effect at a different extent in the 2 cases (nursing management scenario), and some of their consequences were at variance (gynecological problem). Conclusions. The context of available options affects professionals' choices when the alternatives are similar but also when they present diverging features. Professionals need to be aware of such a source of practice variability and are encouraged to consider each option per se before they compare the available options.