The presented paper describes an algorithm for signal quality assessment based on clusteranalysis and also an algorithm for heart rate estimation from PPG signals. This work includesa database which comprises 48 PPG signals collected by a smartphone and 48 ECG signals recordedby an ECG recorder. The accuracy of the quality assessment is 97,5 % on the training set and87,5 % on the test set. The average deviation of the estimated heart rate is 1,39889 bpm.