The present invention relates to a Lactuca sativa seed designated 81-52 RZ, which exhibits a combination of traits including resistance against downy mildew (Bremia lactucae Regel) races B1:1 to B1:17, B1:21, B1:23 and CA-I to CA-VIII, currant-lettuce aphid (Nasonovia ribignisi) biotype Nr:0, corky root (Sphingomonas suberifaciens) race CAI, root aphids (Pemphigus bursarius) and Lettuce Mosaic Virus (LMV), as well as very slow bolting. The present invention also relates to a Lactuca sativa plant produced by growing the 81-52 RZ seed. The invention further relates to methods for producing the lettuce cultivar, represented by lettuce variety 81-52 RZ.
