Objective: To highlight the clinical presentation of CMV endotheliitis and the challenge in diagnosing this condition in recurrent failed penetrating keratoplasty (PK). Methods: Case series Results: There are 3 cases of recurrent failure in PK secondary to CMV endotheliitis presented. Case 1 and 2 were pseudophakic patients, while in case 3, the patient had a previous history of recurrent anterior uveitis. Case 1 and 3 had four and one previous failed PK respectively, while case 2 had endothelial keratoplasty twice before the diagnosis of CMV endotheliitis was made, following positive culture of aqueous humour. The visual acuity ranged from 1/60 to hand movement. All patients had pigmented KP, and two of them had typical coin-shaped KP. Oral valganciclovir was instituted for all patients consisting of 900 mg bidaily for two weeks, followed by 900 mg once daily for six months. Additionally, topical ganciclovir eyedrop 0.5% was given every four hours with topical dexaminim four times a day. Repeated anterior chamber (AC) tap after six months of treatment was negative for CMV in case 3 while cases 1 and 2 are still on treatment. CMV endotheliitis is an increasingly important cause of failed corneal transplant. We recommend anterior chamber tap in suspicious cases of repeatedly failed corneal transplant, regardless of the presence of coin-shaped KP or not. Minimum treatment with oral valganciclovir is important to eradicate the problem, before proceeding with another corneal transplant. Conclusion: It is important to make an accurate early diagnosis by good clinical judgement in preventing loss of corneal endothelial cells. High index of suspicion for CMV endotheliitis as a cause of graft failure must be made especially when the patient presents with coin-shaped KP. Therefore unnecessary treatment resulting from misdiagnosis in these patients can be prevented. Early recognition and treatment of this condition is important to prevent permanent endothelial cell loss and corneal decompensation.