Important test components for performance evaluation, including assessment ofrnbody composition, maximum aerobic capacity, heart rate and pulmonary functionrnevaluation are worth considering. The purpose of this study was to assess therninfluence of Skinfold thickness and some selected cardiopulmonary parameters inrnmiddle distance running performance. Twenty top-class middle distance runners (10rnmales, with Age = 18-26, Weight = 52-68kg, Height = 165-183cm, BMI (kg/m2) =rn17.63-20.90; and 10 females with Age = 18-26, Weight = 41-57kg, Height = 157-rn178cm, BMI (kg/m2) = 14.53-19.99) from Ethiopian Athletics Federationrnvolunteered to participate in the study. Skinfolds were measured at biceps, triceps,rnsub-scapular and supra-iliac regions. Vital capacity (VC), Forced expiratory vitalrncapacity (FVC), Forced expiratory volume in the first second (FEV1), FEV1 %,rnPeak expiratory flow (PEF), Maximum expiratory flow at 25% of maximal VCrn(MEF25), Maximum expiratory flow at 50% of maximal VC (MEF50), Maximumrnexpiratory flow at 75% of maximal VC (MEF75), Maximum mid expiratory flowrnbetween 25% and 75% of FVC (MMEF), Peak Inspiratory Flow (PIF) and PeakrnExpiratory Flow (PEF) were measured by Spirometer. The maximal rate of oxygenrnconsumption (VO2max) was determined using a continuous, incremental exercisernprotocol conducted on an electronically braked treadmill. Cardiotester belt was usedrnto measure heart rate at different level of treadmill testing. Correlation analysesrnwere applied to each variables and run time (performance). Performance was ratedrnby the scoring procedures of the International Amateur Athletic Federation (IAAF).rnIn male athletes, significant negative correlations were observed between skinfoldrnmeasurement at sub-scapular (r = 0.676, and P = 0.046), and supra-iliac (r = 0.798,rnP = 0.01) and IAAF score. High negative correlation were found between sum ofrnfour skinfold measures and IAAF score (r = 0.800, P = 0.010). In the femalernathletes, high negative correlations were found between skinfolds measurement atrnsub-scapular (r = -0.639, P = 0.047), supra-iliac (r = -0.751, P = 0.012), sum of fourrnskinfolds measurement (r = -0.778, P = 0.008), body fat percentage (r = -0.840, P =rn0.002) and IAAF score.rnThere was a negative significant correlation between IAAF score and Percent SubrnMaximum Heart Rate (%HRmax) at 0.01 level of significance (r = -0.843 in femalernand r = -0.865 in male) runners. VO2max (measured as ml/min/kg) was positivelyrncorrelated with IAAF score in male and female runners (r = 0.805, P = 0.003) (r =rn0.859, P = 0.001). IAAF score was positively correlated (p