In this work, special emphasis was dedicated to find conditions to grow AgInSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> thin films with chalcopyrite type tetragonal structure using a procedure based on the co-evaporation of the precursors in a two stage process. Through a parameter study a set of synthesis parameters was found, which allowed us to grow thin films in the AgInSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> phase in a reproducible way. It was also found that the AgInSe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> films present p-type conductivity, a high absorption coefficient (greater than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ) and an energy band gap Eg of about 1.37 eV, indicating that this compound has good properties to perform as absorbent layer in single junction thin film and tandem solar cells. The effect of the deposition conditions on the optical, structural and morphological properties was also investigated through spectral transmittance and XRD (X-ray diffraction) measurements.