The present study was carried out in Lafia Local Government Area of Nasarawa State, Nigeria to evaluate the serum biochemical, minerals, and haematological parameters in pregnant and lactating Ewes in Lafia Metropolis. Eighteen (18) apparently healthy adult sheep comprising 9 pregnant and 9 lactating Ewes were used for this study. The Ewes’ age were between 2.5-3years based on dentition following the standard protocol. 5ml of blood samples were taken by jugular venipuncture from both the pregnant and lactating Ewes, into two sets of collection tubes. The first set were non-heparinized tubes without anticoagulant for serum minerals and serum biochemical analysis while the second set of tubes were the heparinized tubes containing ethylene diamine tetra acetic acid (EDTA) which serves as anticoagulant for haematological analysis. All statistical analyses were done using General Linear Model (GLM) of the Statistical Package for Social Sciences (SPSS version 22). The level of statistical significance was defined as (P<0.05). Fisher’s Least Significance difference (LSD) was used to separate the means. The values of serum Creatinine of lactating Ewes was significantly (P<0.05) higher than the pregnant Ewes values while the values of serum albumin of pregnant Ewes was significantly ((P<0.05) higher than lactating values respectively. The values of serum urea, globulin and total protein of pregnant and lactating Ewes did not differ significantly (P<0.05). No significant differences (P<0.05) were found between the serum mineral values of pregnant and lactating Ewes. The values of Packed cell volume (PCV), haemoglobin (Hb), red blood cell (RBC) and white blood cell (WBC) of pregnant and lactating Ewes did not differ significantly (P<0.05). The findings from this study would aid in understanding the physiological status of sheep