The right of citizens to sue requires that the courts by entering substance of case resolve the issue and minimize refusal to enter the substance. Nonetheless, studying case law shows that some courts do not pay enough attention to this principle, and sometimes by improperly interpreting legal rules, they have challenged the right of citizens to sue and faced it a permanent obstacle. One of these cases is the assumption of multiple potential plaintiffs, some of whom are willing to file a lawsuit, but others are unwilling to do so, and the courts have faced the issue of the necessity or not of their collective litigation; so that some courts by considering necessary the collective litigation of interested parties, have recognized their individual lawsuits as lacking the necessary conditions for hearing; while others do not see any prohibition in their individual lawsuits. By accepting the first approach, the plaintiff cannot legally enforce the other potential plaintiff or plaintiffs to accompany him, nor does he have a way out of the problem not to enter the substance by the courts, and he must give up the litigation. In response to the question of whether collective litigation is necessary in cases with multiple potential plaintiffs, or it suffices to individually start an action, the article by applying descriptive-analytical method tries to critically evaluate the case law regarding some lawsuits such as evacuation and so on and concludes that except in very limited assumptions that individual litigation damages to defendant, collective litigation is not necessary and courts should not challenge their right to individual litigation.