Two T-cell lines were established from peripheral blood mononuclear cells of two Moroccan patients with tropical spastic paraparesis and then named PR52 and PR144. The two cell lines showed a T lineage of activated CD4+ with high density of Tac+ (IL2 receptor). No expression of CD8 was observed. The virus particles were detected by reverse transcriptase activity and the viral antigens were also detected by immunofluorescence (IF) and Western blot. After six months of culture greater than 90% of the cells exhibited HTLVI antigen by IF. Lysate virus particles on Western blot analysis revealed p19,p24, and p53 gag protein similar to those detected in C91/PL virus particles from an adult T-cell leukemia (ATL) patient. gp46 and gp61 were also weakly detected. These two T-cell lines established will serve as substrate for further comparative studies on TSP and ATL isolates.