Laboratory quality control is designed to detect, reduce, and correct deficiencies in a laboratory's internal analytical process prior to the release of patient results, in order to improve the quality of the results reported by the laboratory. The study was done to assess the quality control monitoring and evaluation of Bilirubin & alkaline phosphates and also for inter-laboratory studies of some electrolytes in Nisa Premier Hospital Abuja and the Benue State University Teaching Hospital Makurdi, North central Nigeria. The quality control monitoring & evaluation of Bilirubin and Alkaline phosphates were conducted for two consecutive months using the spectrophotometer (kenza240 TXbiolabo France), and the inter laboratory studies was done and the following electrolytes (K⁺, Na⁺, Cl^-, TCO₂^-) were determined in blood samples at both locations. At both locations determination was performed using Ion Selective Analyzer AC9900 (Audicom, China).The results of quality control showed that Trends (loss of reliability) and shifts (abrupt changes in the control mean) were noted in the results of this study, there were two major trends in July and more shifts in the month of August than in the month of July for bilirubin and two violations of the Westgard Rule for Alkaline phosphates. The results of inter-laboratory assessment of Electrolytes shows a great difference in the mean values of K⁺ between the laboratories in NiSA (3.29 ± 0.40) and BSUTH (12.23 ± 4.65)but imprecision was within acceptable performance. This is similar for all other analytes (Na⁺, TCO₂^-) with exception of Cl^- which clearly indicated marginal performance. The results of the study shows that both imprecision and bias exist between both laboratories but imprecision was within Acceptable performance.