Background: Dental caries is one of the most prevalent dental illnesses in children. Untreated severe caries can damage teeth, requiring pulpotomy to save them. Objective: To evaluate the clinical success rate of treatments involving pulpotomies + IRM (Intermediate Restorative Material, composed of reinforced zinc oxide–eugenol polymers) + preformed metal crowns (PMCs) in primary teeth of children treated at a public university in Mexico. Materials and Methods: A cross-sectional ambispective study was conducted on children aged 10 years or younger, treated at a public university in Mexico. A total of 1281 medical records from February 2018 to June 2023 were reviewed, yielding a sample of 199 children treated with pulpotomy + IRM + PMC. Information was collected via telephone interviews with parents/caregivers to inquire about any symptoms following the pulpotomy and metal crown treatments. Success was defined as the absence of pain, inflammation, or infection. Results: During the study period, the number of teeth treated with pulpotomy + IRM + PMC was 414, with follow-ups ranging from 6 to 69 months. Most participants were girls (54.3%), while 45.7% were boys. Out of the 167 pulpotomy + IRM + PMC treatments included in the study, the clinical success rate was 98.2%. Conclusions: The clinical success rate of primary teeth treated with pulpotomy + IRM + PMCs was high, close to 100%, based on evidence and symptom reports from parents/caregivers. It would be beneficial to implement its use in public health institutions in countries such as Mexico.