Background: Since 2010, Kenya has used SLIPTA to prepare and improve quality management systems in medical laboratories to achieve ISO 15189 accreditation. However, less than 10% of enrolled laboratories had done so in the initial seven years of SLMTA implementation.Objective: We described Kenya’s experience in accelerating medical laboratories on SLMTA to attain ISO 15189 accreditation.Methods: From March 2017 to July 2017, an aggressive top-down approach through high-level management stakeholder engagement for buy-in, needs-based expedited SLIPTA mentorship and on-site support as a rapid results initiative (RRI) was implemented in 39 laboratories whose quality improvement process had stagnated for 2–7 years. In July 2017, SLIPTA baseline and exit audit average scores on quality essential elements were compared to assess performance.Results: After RRI, laboratories achieving greater than a 2-star SLMTA rating increased significantly from 15 (38%) at baseline to 33 (85%) (p  0.001). Overall, 34/39 (87%) laboratories received ISO 15189 accreditation within two years of RRI, leading to a 330% increase in the number of accredited laboratories in Kenya. The most improved of the 12 quality system essentials were Equipment Management (mean increase 95% CI: 5.31 ± 1.89) and Facilities and Biosafety (mean increase [95% CI: 4.05 ± 1.78]) (both: p  0.0001). Information Management and Corrective Action Management remained the most challenging to improve, despite RRI interventions.Conclusion: High-level advocacy and targeted mentorship through RRI dramatically improved laboratory accreditation in Kenya. Similar approaches of strengthening SLIPTA implementation could improve SLMTA outcomes in other countries with similar challenges.