We present a computationally efficient Fano detection algorithm with an iterative structure for V-BLAST systems. As our previous work, we introduced a Fano-based sequential detection scheme with three interrelated steps whose computational loads are excessive. To deal with the computational inefficiency, the proposed algorithm is redesigned by the addition of two steps: preparation and iterative tree searching. In particular, it employs an early stop technique to avoid the unnecessary iteration or to stop the needless searching process of the algorithm. Computer simulation shows that the proposed scheme yields significant saving in complexity with very small performance degradation, compared with sphere detection (SD).