Introduction: The fluoroquinolones antibacterial agents are one of the fastest growing groups of drugs in recent years. The vari ous side chains on it can be altered and the resulting analogues are evaluated for their anti-microbial and antitubercular proper ties. Most of these agents are substituted at the 7 positions by nitrogen heterocycles. Lomefloxacin at C-7, which represents a site amenable to significant modification. Objective: Based on evidence of research results and in search of new bioactive molecules in the fluoroquinolones, a of N substituted piperazinyl quinolones have been designed, synthesized, characterized and evaluated for their antibacterial activity and antitubercular activity. Method: A series of 2-((5-chloro-1, 3, 4-thiadiazol-2yl) thio)-1-(4-subs.) ethanone (4a__ampersandsignndash;4j)were prepared by diazotization of amines (3a-3j) in concentrated HCl in the presence of Cu-powder. The reaction of(4a-4j) with piperazinyl quinolone (lomefloxa cin) in DMF yield (5a-5j). The synthesized compounds were evaluated against some Gram-positive and Gram-negative bacte rias and antitubercular activity against Mtb WT H37Rv. Result: The structure of the synthesized compound was confirmed by their IR, 1HNMR, data. The antibacterial data revealed that all substituted derivatives (5a to 5j), are found to be least active against Gram-positive and Gram-negative organisms. Among all of the tested compounds,5b(Lomefloxacin derivative) exhibited excellent antitubercular activity against Mtb WT H37Rv (MIC0.8 __ampersandsignmicro;g/ml) which is comparable to that of standard. (MIC 0.8 __ampersandsignmicro;g/ml) Conclusion: Although the nature of the C-7 substituent is known to enhance quinolone activity in bacteria but results of the present study reveal that the synthesized derivative shows significant antitubercular property but poor antibacterial activity.