Three cases presenting with systemic lupus erythematosus (SLE) and minimal change nephrotic syndrome (MCNS) are reported in this paper. All cases were female; they abruptly developed nephrotic syndrome at the age of 30, 11 and 23 years, respectively. In Case 1, the diagnosis of SLE was based on fever, butterfly rash, Raynaud's phenomenon, leukopenia, lymphopenia, hypocomplementemia, a high titer of anti-DNA antibodies, positive DNA and LE test, and the presence of anti-nuclear antibodies (speckled pattern). In Case 2, the diagnosis was based on butterfly rash, central nervous system involvement, lymphopenia, hypocomplementemia, a positive LE cell phenomenon, a high titer of anti-DNA antibodies and a positive DNA test. In Case 3, the diagnosis was based on photosensitivity, alopecia, lymphopenia, hypocomplementemia, a high titer of anti-DNA antibodies, a positive DNA test and a positive LE cell phenomenon. In these three cases, initial symptoms were puffy face and pretibial edema which occurred suddenly. These symptoms disappeared completely after either corticosteroid therapy or a combination therapy using corticosteroids and immunosuppressive drugs. These patients took a favorable course and no aggravation was noted in the findings of urinalysis and renal functions. In two of these cases, the diagnostic criteria for SLE were satisfied, but the remaining patient fulfilled only three criteria except for renal disorder. In each of these cases, minor glomerular abnormalities were disclosed by renal histology. It seems likely that SLE was complicated by MCNS in these cases. From these cases, it is suggested that there is a possibility of immunological abnormalities associated with SLE and MCNS.