Competitive pressure and desire for success drive enterprises in general to introduce product and process innovations faster and at lower costs than their competitors, a challenge that is becoming increasingly significant in the rapid-changing economic world. Therefore, entrepreneurs, researchers and policy makers have taken a special interest in the different mechanisms and strategies for innovation achievement, which are not only determined by factors internal to the firms, but also by external interactive processes involving diverse relationships among the market agents. In this context, the objective of the current paper is to investigate the likelihood of an enterprise established in Bulgaria to engage into co-operations for innovation conditional on numerous internal and external factors.