A descriptive study on assessment of medicines cold chain storage conformity with World Health Organization (WHO) requirements in public health facilities was carried out in Dar es Salaam and Dodoma regions. Storage conformity in selected health facilities was assessed by monitoring temperature using temperature data loggers mounted in the refrigerators for a period of 30 days. Results indicated almost half of the health facilities 48.5% visited, did not significantly (P = 0.031) comply with storage temperature (+2°C to +8°C) as per WHO requirement because all recorded Mean Kinetic temperature (MKT) > 8°C. In rural areas, 59.2% of visited health facilities adhered to the WHO recommended storage temperature while in urban areas only 31.6% complied. The study has established electricity failure in urban and lack of gas in rural areas coupled with absence of contingency plan as major challenges to WHO temperature conformity in storage of cold chain medicines in health facilities in Tanzania.