The relationship between the threading dislocation density (TDD), the generation (τ g ) and recombination lifetime (τ r ) in relaxed n-type In .53 Ga .47 As is investigated for a series of p+n junction diodes, containing a TDD ranging from 10 5 to 10 10 cm −2 . The TDs are generated intentionally by lattice-misfit growth on semi-insulating (SI) InP and GaAs substrates. The lifetimes have been extracted from diode current-voltage (I-V) and photoluminescence (PL) analysis showing that TDDs affect their values above a density of about 1 × 10 7 cm −2 (τ g,E ~ 0 ) and about 1 × 10 8 cm −2 (τ r and τ PL ), which can be well-explained by the charged dislocation cylinder model. In addition, a detailed comparison between the results from deep level transient spectroscopy and from the diode characterization is performed, showing that the responsible G/R center shifts toward mid-gap in In .53 Ga .47 As and transfers from a native point defect (PD1) to a TD (E2/H1). Finally, the classical concept of generation lifetime and recombination lifetime in terms of dislocations is discussed based on the results.