First principles density functional calculations were carried out to study the electronic structure and thermoelectric properties of LnN (Ln = La and Lu) using the full potential linearized augmented plane wave (FP-LAPW) method. The thermoelectric properties were calculated by solving the Boltzmann transport equation within the constant relaxation time approximation. The obtained lattice parameters are in good agreement with the available experimental and other theoretical results. The calculated band gaps using the Tran-Blaha modified Becke-Johnson potential (TB-mBJ), of both compounds are in good agreement with the available experimental values. Thermoelectric properties like thermopower (S), electrical conductivity scaled by relaxation time (σ/τ) and power-factor (S 2 σ/τ) are calculated as functions of the carrier concentration and temperature for both compounds. The calculated thermoelectric properties are compared with the available experimental results of the similar material ScN. © 2015 AIP Publishing LLC.