Recently, Data Mining Classification has found its remarkably outstanding hold in the medical field. Machine learning is an emerging field in understanding and analyzing huge amount of healthcare data. This research comes out with the performance analysis of various classification techniques on healthcare datasets using machine learning tool Weka. We applied different classifiers on four medical datasets to find out the best classification algorithm. With the results obtained, it is found that J48 algorithm and Random Forest algorithm shows most promising results among all classification algorithms.