In some situations, data can not be measured due to the devices used in the health sciences. They fall below one or more detection limits. Nondetects analysis can be used in this situation. Several methods are used as Nondetects analysis. Nondetects-Data Regression and Multiple Imputation methods were compared in this study. Both methods were compared according to root mean square error. Various non detects data proportions, sample size and R-suared. Some general suggestions are given on which tests should be used.