Aim: To describe a small series of six cases of children who were diagnosed as uncooperative and referred to general anesthesia to complete their dental treatment. These children were actually exhibiting pain-related disruptive behaviors during previous dental treatments; we determined the reasons for ineffective anesthesia. Background: One of the most common reasons for disruptive behaviors in children during operative dental treatment is the experiencing of pain during treatment. Disruptive behavior may lead to treatment under general anesthesia. Case description: Parents of six uncooperative children referred to general anesthesia for dental treatment, arrived at our clinic, because they wanted a second opinion. The children were found to be nonresponsive to the common anesthetic technique and were treated by several approaches to increase the effectiveness of anesthesia. These included supplementary anesthesia to accessory innervation (in three cases), changing brands of anesthetic (in two cases), injecting the maximal dose at once to prevent tachyphylaxis, and waiting 5 minutes to achieve effectiveness of anesthesia (in one case). After achieving effective anesthesia, all the children fully cooperated during the operative treatment. Conclusion: Ineffective anesthesia can lead to severe disruptive behavior when continuing the treatment irrespective to the sensation of pain. Several approaches were used to increase the effectiveness of anesthesia resulting in cooperation of the pediatric patients. Clinical significance: Behavioral response to ineffective anesthesia may be diagnosed as uncooperativeness. Effort should be put to differentiate between ineffective anesthesia and uncooperative patient.