Madrid's Anti-Doping Laboratory has had its suspension lifted by the World Anti-Doping Agency (Wada).
The laboratory was sanctioned in June 2016 after Wada said the Spanish anti-doping agency AEPSAD had failed to comply with international standards.
The suspension had prevented the Madrid lab from carrying out any Wada-related anti-doping activities including all analyses of urine and blood samples.
Wada said it was confident Madrid would "operate to high standards."
AEPSAD (Agencia Espanola de Proteccion de la Salud en el Deporte) had missed a deadline for required changes to its drug-testing procedures, but its removal from Wada's non-compliant list in March was followed by an inspection of the Madrid laboratory.
"We would like to thank the laboratory for their continued cooperation throughout this process," said Wada director general Olivier Niggli.
"This decision allows the laboratory to resume all of its anti-doping activities, including all analyses of urine and blood samples, with immediate effect."