Abstract Several approaches have been proposed to reduce debugging costs through automated software fault diagnosis. Dynamic Slicing (DS) and Spectrumbased Fault Localization (SFL) are popular fault diagnosis techniques and normally seen as complementary. This paper reports on a comprehensive study to reassess the effects of combining DS with SFL. With this combination, components that are often involved in failing but seldom in passing test runs could be located and their suspiciousness reduced. Results show that the DS-SFL combination, coined as Tandem-FL, improves the diagnostic accuracy up to 73.7% (13.4% on average). Furthermore, results indicate that the risk of missing faulty statements, which is a DS’s key limitation, is not high — DS misses faulty statements in 9% of the 260 cases. To sum up, we found that the DS-SFL combination was practical and effective and encourage new SFL techniques to be evaluated against that optimization